Stop trying to access tiles off edge of map
Abort hit checks as soon as tile is out of map
Move ai action limit check

.. to prevent possiblity of ai moves completing during player turn.
Separate conversion from tallying
2-line fix for edgescrolling in Battlescape.

When scrolling diagonally and sliding the cursor to a straight
lateral scroll, the vertical component wasn't negated
Merge pull request #625 from kevL/edgescroll_fix_kL

2-line fix for edgescrolling in Battlescape.
Merge pull request #621 from cfailde/overlap

Move ai action limit check
Merge branch 'bug227' of https://github.com/cfailde/OpenXcom into cfailde-bug227

Conflicts:
	src/Battlescape/TileEngine.cpp
Merge pull request #624 from cfailde/bug246

Separate conversion from tallying