booster: attr_timeout: Read timeout from booster fstab
booster: attr_timeout: Read timeout from booster fstab

In order to expose the timeout values for stat and inode
caching, this commit introduces a new fstab option "attr_timeout"
that defines the number of seconds for which a looked up inode
or a stat()'ed structure is valid in the cache.

Signed-off-by: Anand V. Avati <6a1810c170bd423868ce2e225ecea39d80cade0f@dev.gluster.com>

Kaushikbv/Gluster,Kaushikbv/Gluster,Kaushikbv/Gluster