add new map Hopes Anchor by @NukemBro

http://resource.openra.net/maps/1368/
remove maps

closes #5458
added Oasis Conquest

http://resource.openra.net/maps/1470
added Desert Twister by @psydev

http://resource.openra.net/maps/990
added Vladimir's Folly

http://resource.openra.net/maps/1639/
Fix the --png utility command. Closes #6845.
Merge pull request #6841 from Mailaender/hopes-anchor

Added a new map Hopes Anchor
Merge pull request #6844 from Mailaender/new-d2k-maps

Added new maps to the Dune 2000 mod
Merge pull request #6847 from pchote/fix-utility

Fix the --png utility command.
remove Convergence and River War maps
Merge pull request #6842 from Mailaender/map-scrap

Removed several maps from the Red Alert mod
remove the legacy Lua library
remove lonely tab
port gdi03 to the new Lua API
disallow SAM site capturing
alert more guards