Improved "Cross mount points" functionality

Currently the NetBackup client check to see if ALL directories are mount points or not, regardless of this setting.  Each check is taking one to two seconds.  That doesn't seem like much, but when you have 25,000 mount points, it adds up REALLY fast. It would be nice, and much more efficient if the check to determine if a directory is a mount point is disabled if the Cross mount points option is enabled.  After all, if NetBackup is supposed to cross the mount point, how does it matter if it is one or not?