Checks for 'dict' in `x.__class__.__name__` b/c
neither `type()` nor `isinstance()` is available.

!!   Not tested with an actual   !!
 !!  configured `ext_pillar` yet  !!

- jinja on RHEL/CentOS 6 has no 'mapping'
  test (see salt-formula issue #193)
- {% do ... %} allows no assignment, only
  function calls
- of course, `type(foo) is dict` doesn't
  work because it's no jinja test
- maybe `.isinstance()` would be nicer/more
  reliable

Using the old salt.engines pillar and merging it with the new
salt.[master|minion].engines pillar.
This way, it doesn't break previous behavior and permits to define
common engines on master and minion.
In the merge, the salt.[master|minion].engines pillar takes precedence
if conflict as it's the more specific pillar.

the engines are now configured using the following pillars:

* salt.master.engines
* salt.minion.engines

instead of a global salt.engines pillar.

Note: the pillar.example provided seems to assume this behaviour.
(the pillar is salt.master.engines.slack and not salt.engines.slack)

Signed-off-by: Rene Jochum <rene@jochums.at>

Signed-off-by: Rene Jochum <rene@jochums.at>

This avoids problems when values are strings containing colons. And it
mimicks what was already done for the salt-minion's configuration file.

Fixes #233.

This makes it easier for users to check the status of jobs that ran into
a timeout.

With a simple pillar like this::

    $ sudo salt-call --config-dir /srv/etc/bootstrap --pillar-root /srv/pillar pillar.get salt:pillar_roots
    local:
        ----------
        base:
            - /srv/pillar

This was generated in /etc/salt/master.d/f_defaults.conf::

    # highstate format, and is generally just key/value pairs.
    pillar_roots:base:- /srv/pillar
    #

Resulting in parse errors by salt::

    $ sudo salt '*' state.highstate
    [ERROR   ] Error parsing configuration file: /etc/salt/master.d/f_defaults.conf - while scanning a simple key
      in "<string>", line 531, column 1:
        pillar_roots:base:- /srv/pillar
        ^
    could not found expected ':'
      in "<string>", line 532, column 1:
        #
        ^
    [ERROR   ] Error parsing configuration file: /etc/salt/master.d/f_defaults.conf - while scanning a simple key
      in "<string>", line 531, column 1:
        pillar_roots:base:- /srv/pillar
        ^
    could not found expected ':'
      in "<string>", line 532, column 1:
        #
        ^

This patch will fix it as such::

          ID: salt-master
    Function: file.recurse
        Name: /etc/salt/master.d
      Result: True
     Comment: Recursively updated /etc/salt/master.d
     Started: 11:37:12.946823
    Duration: 6255.296 ms
     Changes:
              ----------
              /etc/salt/master.d/f_defaults.conf:
                  ----------
                  diff:
                      ---
                      +++
                      @@ -528,7 +528,9 @@
                       # Pillar is laid out in the same fashion as the file server, with environments,
                       # a top file and sls files. However, pillar data does not need to be in the
                       # highstate format, and is generally just key/value pairs.
                      -pillar_roots:base:- /srv/pillar
                      +pillar_roots:
                      +  base:
                      +    - /srv/pillar
                       #

Resulting in::

    # highstate format, and is generally just key/value pairs.
    pillar_roots:
      base:
        - /srv/pillar
    #

This commit fixes how `pillar_roots` are generated and after this fix the
generated configuration does not contain any unnecessary new lines:

```yaml
pillar_roots:
  base:
     /srv/salt/dir1
  dev:
     /srv/salt/dir2
     /srv/salt/dir3
  locale:
     /srv/salt/dir4
```

Before this commit the pillar_roots in `f_defaults.conf` for master would be
generated with a lot of empty lines in between directories, like this:

```yaml
pillar_roots:

  base:

     /srv/salt/dir1

  dev:

     /srv/salt/dir2

     /srv/salt/dir3

  local:

     /srv/salt/dir4

```

The minion configuration is not affected and renders fine.

Added config setting for:

* pillar_source_merging_strategy

Salt writes it's schedule file to /etc/salt/{minion,master}.d/_schedule.conf

We don't want to stomp all over Salt's files, but we do want a pristine
starting point to lay down our managed config. So we use clean: True on the
file.recurse call, but we tell it to ignore files that start with an _

We have to rename the current config file (_defaults.conf) because it will be
ignored by the rule that ignores Salt's _* config files.

This also means we need to clean up old config files (_defaults.conf) and
restart the service if we cleaned it up.

see pillar.example for configuration

If those options are set in pillar data, the jinja template
salt/files/master.d/_defaults.conf would fail to compile trying to
evaluate non-existing variables.

Replace those variables with the corresponding dictionnary entries.

This is only needed for salt versions older than 2014.7 that do not
define the global "salt" variable in such context.

Most include do not expect salt to be something else than the usual salt
variable giving access to all the salt modules. Instead we use cfg_salt.
And for consistency we rename the master/minion variables to
cfg_master/cfg_minion too.

In Python 3, dict.items() is already an iterator while dict.iteritems() no
longer exits. In Python 2, dict.items() is not an iterator but it works
and the small performance hit doesn't really matter for the salt config
pillar data which is really small.

Otherwise you get an “ValueError: too many values to unpack” exception
when you make use of those entries in your pillar data.