fs: Add truncate() support for userfs
fs/unionfs: Add truncate() support to the unionfs
fs/tmpfs: Add ftruncate() support to tmpfs
syscall/: Add system call support for ftruncate()
net/route: Adding ftruncate() support eliminates an issue in file-based routing table management.
fs: Add basic framework to support truncate() and ftruncate(). The infrastructure is complete. Now, however, the actual implementation of ftruncate() will have to be done for each file system.
