Remove bitrotted tab source artwork.
Add opposing-faction tab art for aircraft and navy,
Fix incorrect soviet tab image coordinates.
Enable correct tab images for helicopters and aircraft.
Fix bogus inconsistencies in the ra tab images:

- Soviet-normal tab glyphs were off by 1px.
- Allied-selected tabs had random semi-transparent pixels.
- Most tabs had a discoloured pixel near the left edge.
Sort Changes
Merge pull request #5927 from MustaphaTR/ra-building-sort

Fixes #5914
Merge pull request #5926 from pchote/ra-tabs

Fixes #5915
Explosive Oil Derricks
Update fort-lonestar.lua
Merge pull request #5938 from abcdefg30/fortlonestar

Fixed a bug in Fort Lonestar
disable tech properly
Merge pull request #5940 from Mailaender/fort-lonestar-tech-disable

Fixed unbuildable high-tech on Fort Lonestar
Merge pull request #5930 from MustaphaTR/ra-oil-explode

RA - Explosive Oil Derricks