title: Move and Lock Vertex
author: tiglari

This plugin is responseible for the vertex RMB commands Move Vertex,
Lock Vertex, and Clear Locks.  Move Vertex starts an extremely slow and
deliberate key-driven vertex-movement scheme, and Lock Vertex 'freezes'
certain vertexes for its operation.  Unfortunately, Lock Vertex has no
effect on ordinary vertex dragging because I haven't managed to grok
the vertex dragging code well enough to merge it in.  Clear Locks of
course clears the locks.

This isn't as good as Worldcraft/Hammer vertex movement mode, but it
can help with some problems (thanks to discussions with quantum_red,
I've got some ideas about real vertex-movement; maybe it will appear
in QuArK 6.4).
