Added base support for CLAIM_DELEGATE_PREV

Signed-off-by: Venkateswararao Jujjuri "<jvrao@linux.vnet.ibm.com>
Added nfs4_populate_revoked_delegs() to read revoked handles from
stable storage into memory.

Signed-off-by: Venkateswararao Jujjuri (JV) <jvrao@linux.vnet.ibm.com>
Corrected code under deleg_reclaim_current

Signed-off-by: Venkateswararao Jujjuri (JV) <jvrao@linux.vnet.ibm.com>
Added support for recording revoked file handles.

Signed-off-by: Venkateswararao Jujjuri (JV) <jvrao@linux.vnet.ibm.com>
Added support to check if the deleg_reclaim_prev can be granted.

Signed-off-by: Venkateswararao Jujjuri (JV) <jvrao@linux.vnet.ibm.com>
Simple fixes
Fix for function that removes delegations from list during state_unlock()
Filter out FSAL_O_RECLAIM from openflags.
Fix deleg_revoke bug
Select filename in open4_open_owner according to the claim.