Use install instead of installmissing if Chocolatey >= 0.9.8.24

X-ref: #13980

This also adds a chocolatey.chocolatey_version function and does some
DRY cleanup so that the error message and exception are raised in
_find_chocolatey() instead of in 6-8 different places.
Have CLI check job cache

Fixes an issue wherein returns might be missing from the CLI because of
a race condition between find_job and the timeout.
Update gitfs documentation

This adds all the new authentication options, and also moves most of the
usage examples into the gitfs walkthrough. The walkthrough has also
undergone considerable restructuring.
Add new config parameters for gitfs auth
Add pygit2 auth to gitfs
Fix ssh exec module docstrings

You don't need to end a line in a backslash within a docstring. Besides,
doing so leaves large gaps in the line when rendered by sphinx.
Update gitfs test opts to reflect new gitfs config opts
Actually, pygit2 supports auth in 0.20.3 as well

Allow for a minimum version of 0.20.3. The one difference found so far
is that pygit2.Remote.fetch() returns a class instance starting in
0.21.0, so this commit also changes the logic that checks for the number
of received objects so that it works irrespective of version.
Update docs to reflect pygit2 auth support in 0.20.3
Remove obsoleted variable PYGIT2_TRANSPORTS
Set USERNAME env var manually in test suite

This works around a known issue in GitPython when the USERNAME
environment variable is missing.
D'oh, needed to capitalize USERNAME
Make salt cloud bail on error'ed ssh commands
Fallback to `rsync` if `scp` is not available.

This happens with the Cent 5 image from Rackspace
SmartOS esky packaging of 2014.7

Resulting builds can be used either with zeromq or with raet
Get effective username using pwd.getpwduid()
Merge pull request #15123 from cachedout/cli_check_cache

Have CLI check job cache
Merge pull request #15153 from nshalman/esky-improvements-2014.7

SmartOS esky packaging of 2014.7
Revert "Reload grains with modules for states"
Merge pull request #15157 from saltstack/revert-15136-reload-grains-with-modules-for-states

Revert "Reload grains with modules for states"