Add a NFS protocol helper class that can modify exports of a Ganesha
server based on share access rule changes. This allows the manila
guests to access shares in CephFS backend using NFS protocol through
NFS-Ganesha gateways.
And while adding the driver's helper class that subclasses Ganesha
library's GaneshaNASHelper2 identified minor issues in the
Ganesha library. Fix the issues by:
* escaping special character '=' in values of Ganesha conf's string
options, except for option CLIENTS, by enclosing the values with
double quotes.
* add a new callback interface to GaneshaNASHelper class to
allow driver's to perform Ganesha FSAL specific cleanup.
Partially-implements: bp cephfs-nfs-support
Depends-On: I5234bae0595efdcd30305a32bf9c121072a3625e
Change-Id: I9709d94cdb6f8d3e92b8dfc91b2ec4e154a8ec20