Adding file:// URL support for salt mako template lookup and mine_get acl support (Issue#5467)

(1) Adding file:// URL support to lookup mako templates on local file system...
If mako templates are already present on a local file system on a
minion, it can use file:// URL to lookup a local copy. This  in addition
to salt:// url support that is already present, which fetches a copy
from a salt server.

(2) Issue#5467 : 	Adding master side acl support for mine.get

Not sure if you accept two different commits per pull request. If not then I will try to create separate pull requests.