Disallow unlock request during Grace period

Signed-off-by: vrajavarman <ravanjia@in.ibm.com>
Do not check for grace period in SECINFO.

Signed-off-by: suhrud <supatank@in.ibm.com>
Make sure state is valid before dereferencing it
Signed-off-by: Poornima Gupte <poornima.gupte@in.ibm.com>
Import ANSI C cityhash.

The implementation is the ANSI C adaptation (by Alexander Nusov)
of Google's original C++ implementation.

The whole is covered by an MIT-style license.

Signed-off-by: Matt Benjamin <matt@linuxbox.com>

Conflicts:
	src/support/CMakeLists.txt
Introduce new nfsv4 file handle.
Prototypes for data struct changes and new functions.
Changes for nfsv4 xattr's due to new nfsv4 file handle.

I simply commented code where variables no longer exist. I also left
explanations of what functionality has been removed though this code
was not functional to begin with.
referral changes due to nfsv4 file handle changes.
Changes to init procedure due to avltree and hashtable additions for pseudofs.
More changes due to new nfsv4 file handle.
Replace use of the reverse_tab pseudofs node list with direct reference of avltree node.
Add avltree, hashtable, print, other functions to be used in pseudofs.
Also add some global variables to be used in pseudofs.
nfs4_ExportToPseudoFS() updated for new pseudofs avltree/hashtable.
nfs4_CurrentFHToPseudo() updated for new pseudofs avltree/hashtable
nfs4_PseudoToFhandle() updated for new pseudofs avltree/hashtable
nfs4_op_lookup_pseudo() updated for new pseudofs avltree/hashtable
nfs4_op_lookupp_pseudo_by_exp() updated for new pseudofs avltree/hashtable
nfs4_op_readdir_pseudo() updated for new pseudofs avltree/hashtable
One extra free caused segfaults.
We can't access an associated export entry for a pseudofs node.