Added unit tests for undo after moving files and for copying a directory.
The latter crashed; found a nice porting bug in konq_undo:
QVector::iterator end = v.end(); while (it!=end) { if (...) { it = v.erase(it); } else ++it; }
This is invalid because erasing elements changing the end, so in such a case we can't cache end().

Also fixed 61442: after renaming a file, undo says "Undo Rename" now instead of "Undo Move".