Added syscalls for, and implemented sys_create_link(), sys_remove_dir().
Implemented link(), unlink(), rmdir().
Fixed the inconsistent path buffer handling in the user|sys vfs functions; the
path buffer is now exactly SYS_MAX_PATH_LEN from userland (incl. terminating
null byte).
git-svn-id: file:///srv/svn/repos/haiku/trunk/current@748 a95241bf-73f2-0310-859d-f6bbb57e9c96