Add salt.utils.expr_match()
Replace expression matching with salt.utils.expr_match()
Add salt.utils.check_whitelist_blacklist()
Add env whitelist/blacklist to gitfs
Add default values for new config parameters
Clear remote fs backend env cache on master start

Clear remote fileserver backend env cache so it gets recreated during
the initial loop_interval. Allows envs to be rebuilt if changes are made
to an env whitelist/blacklist.
Add new config parameters to the docs
remove unused import
Merge pull request #10761 from terminalmage/gitfs-env-whitelist

Add environment whitelist/blacklist to gitfs backend