Warzone 2100 Graphic Mods tools

Roclies tune up sky box still need better texture.
Will add more alpha later so moon can be seen more often

More work on the video dumper.
Clean up wzencode.py
Add more content to README
Attempt to optimize video dump code by factoring out mallocs into
videoDumpToDisk() so we only do them at start of dump.

Adding new sky texture for Rockies tile set so now we have 3 types of sky arazona urban AND rockies

adjusting sky textures almost happy with them.

more texture adjusting for urban sky

removing seams from skybox joins

placehpolder for urban sky

Added full animation capability to PIE3 format, changed bits and pieces from integer to floating point along the line.

inverting moon texture

Fixed tooltip box to render using REND_ALPHA rather than REND_OPAQUE - this was causing it to invert the colours on the skybox when tooltips appeared.