Initial implementation of git pillar

This isn't a particuarly pretty implementation, but it does work.

There are a few "gotchas" with this implementation-- since the pillar builder uses the local fileclient you have to have some directory which has all of the files-- to work with this i've set it up so you have to specify a branch+repo combination.

Ideally we'd need to do some work on the fileclient to add a new class which is something like "gitremote" that can then manage all of the file getting/caching/etc.
add ability to pass defaults to included pillar sls
Fix traceback in sys.doc, sys.list_functions

This fixes #5779. In addition, it adds support for an arbitrary number
of positional arguments.
Merge pull request #5788 from terminalmage/issue5779

Fix traceback in sys.doc, sys.list_functions
Update network.py

Update data as required due to network interface changes. Thanks to help from @cgoudie.
Update AUTHORS

I contribute.
Merge pull request #5790 from jhutchins/patch-3

Update AUTHORS
Document the `env` arg for cmdmod functions, Fix #5772
Add additional debug logic for reading templating files

Ref #5776
Merge pull request #5789 from jhutchins/patch-2

Update network.py
Trigger the controlling minion process to refresh grains also
Merge pull request #5792 from basepi/envdoc5772

Document the `env` arg for cmdmod functions, Fix #5772
Make the `except` less general
Allow all functions to be returned. Refs #5779.
Improve `sys.list_functions` tests.
Update network.py

refresh instead of reload
Some more `sysmod` testing improvements.
Merge pull request #5797 from cgoudie/patch-1

Update network.py
Allow for all documentation to be returned.
Merge pull request #5796 from s0undt3ch/hotfix/modules.sysmod

Fix travis and sys.list_functions