Fixes for various bugs noticed by Coverity static analysis tool.
Add new maps: Gamma (3p) and Melting (6p)
Update changelog

(cherry picked from commit 6b0ceca623f710dc5444d35cb1e1fa7965ee684a)
Update Changelog

(cherry picked from commit 8d015ad27b5317877b8b9ee8f69c1a291c9278e8)
Merge branch 'bugfixes'

Conflicts:
	src/scriptfuncs.cpp
Fix compile issue broken in 5f32c3eafe26c959045f10b21bea2efc69c770d2
fix flickering of trees (and some other objections) see 5ef1eff3eaffd63bbd1a7f3e0d8e1971c9d78f2e for initial changes.