Added shared NFS inode DB code patch.
Added missing changes from CMake system.
Merge branch 'shared_nfs' of git://github.com/sfayer/cvmfs into shared-nfs
Integrated sqlite shared NFS with the following changes:
  o) Prepare the get-inode, get-path, and issue-inode statements
     only once in the module initialization
  o) Custom busy handler that uses SafeSleepMs with exponential backoff,
     the sqlite handler uses sleep() which interferes with the ALARM signal
     handler
  o) Moved setting sqlite to multi-thread mode to cvmfs.cc.  It is the
     default anyway
  o) Use atomic integers for statistics
  o) Cosmetics