mounttablelib: Persist permissions to the underlying file system.
mounttablelib: Persist permissions to the underlying file system.

I also got rid of references to TAM's (tagged acl maps).  Also
changed acl to al everywhere I noticed since we don't have
access control lists, we have access lists.

The al's are stored as JSON to make them easy to read and also
edit if need be.

MultiPart: 2/3
Change-Id: I9ec5e2553a33fb3b61fccd9b0da67b2b66569f14

viksit/chat,viksit/chat,viksit/chat,vanadium/chat,vanadium/chat,viksit/chat,vanadium/chat,vanadium/chat,viksit/chat,vanadium/chat