Adding support for S3 as a fileserver backend
Update s3fs.py
use sets for platform tests for enabling/disabling modules
harmonize at.BAD & system.UNSUPPORTED => disable
Fix some pep8
Remove check_dns arg from minion_config, Fixes #4811

All use of the check_dns arg was removed in
598d715d28b15202cdba87b6882ef96c90d4f075.  No longer needed.

Arg was removed from both apply_minion_config and minion_config in
config.py, as well as all their call points.
Add **kwargs so we don't break API calls
Update s3fs.py
Merge pull request #4941 from hulu/virtual-disable

harmonize at.BAD & system.UNSUPPORTED => disable
Only import pwd in one place, Fixes #4808

Also make it so windows minions can import master.py without barfing on
the original pwd import
Small copyedit and pep8 fix
Use salt.utils.is_windows()
fix some Sphinx warnings
Merge pull request #4962 from hulu/sphinx-warnings

fix some Sphinx warnings
Merge pull request #4961 from basepi/pwd4808

Only import pwd in one place, Fixes #4808
Remove **kwargs from salt.utils.daemonize_if, Fixes #4807
Fix OSX installation docs for macports, Fix #4951
Add salt-call master option
Hook master option from cli into opts dict
This clutters the logs with all of the failed attempts to load

execution modules that should not be loaded, this makes a mess
at the info setting