* This allows KPath to not allocate a buffer when initialized
without path.
* Added test cases for this.
* Added test for LockBuffer().
* Enhanced tests to allow building them in debug mode.
* Moved calling vfs_normalize_path() into own private method.
* Improved error codes; B_NO_MEMORY is now only returned if the
allocation actually failed.
* If used with LAZY_ALLOC, Path() and LockBuffer() are now allowed
to return a NULL path.