https://github.com/saltstack-formulas/salt-formula/issues/64

Fixes issue where a gitfs remote that has no child options would cause an
error. Also fix up bad yaml in pillar example.

Commit 2b51a6f0c3 introduced options for gitfs_remotes in a pillar by using a jinja test to see if a parameter is a mapping (dict etc.). This feature however is only available in jinja 2.6 or newer (see http://jinja.pocoo.org/docs/dev/templates/#mapping).
Although this version of Jinja is available on Ubuntu, other OS / package managers do provide older versions (2.2.1 in RedHat 6).

This change makes use of the "iterable" test which should do the exact same thing.

Reference about this config value: http://docs.saltstack.com/en/latest/ref/configuration/master.html#yaml-utf8
Reference why this might be useful: https://github.com/saltstack/salt/issues/3436#issuecomment-61225863

This allows users to easily add configuration settings that the formula
doesn't yet provide, without having to modify the existing templates.

Fixes #48

See #37 "Fixed file_roots config generation with several environment"

Fixed an apparent typo in the autoreject_file setting (which was listed as autorejecte_file)

made fileserver_backend and gitfs_remotes look more like expected