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)

The salt-cloud packages automatically pull in the pycrypto and libcloud
dependencies for RedHat and Debian (at least when using the SaltStack
repos), so it doesn't really make sense to install these dependencies
using pip. By default we no longer use pip, but the old behaviour can be
restored by setting 'salt:use_pip' to True in the pillar.

There could probably be a case made for removing the pip stuff
altogether, but we will leave it in for the time being to preserve some
backwards compatibility.

Rasbian reports back the following grain values:

local:
    ----------
    os:
        Raspbian
    os_family:
        Debian
    osarch:
        armhf
    osmajorrelease:
        8
    osrelease:
        8.0

Ubuntu reports back the following grain values:

local:
    ----------
    os:
        Ubuntu
    os_family:
        Debian
    osarch:
        amd64
    osmajorrelease:
        14
    osrelease:
        14.04

For Raspbian the osarch needed to be changed from other Debain os_family
distributions.
For Ubuntu the osrelease value is needed instead of osmajorrelease as other
Debian os_family distributions.

Part of #180

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

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

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

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

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

repo.saltstack.com handles all currently supported Debian releases as well
as all supported Ubuntu releases so this change should be fine.

Part of #180.

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.

Without this change, importing map.jinja in config files (as opposed to
SLS files) causes a rendering error because `slspath` isn't defined.
The `salt_settings.key_url` variable gets used only in
`salt/pkgrepo/debian/init.sls`.