RTS: Properly detect memory allocation failures.
RTS: Don't initialize useless CRect object.
RTS: Call Delete() for string only once for one point.

Delete() call isn't free and it make sense to halve the needed calls.

Also fixes CID 1224583
CPolygon: Cosmetics
Save the solution files with Visual Studio.
RTS: Fix artifacts after scaling due to improper rounding.
RTS: Use SSE2 conversion for rounding.
Rasterizer: Remove VirtualDub dependency to detect SSE2.
MainFrm: Don't overwrite last window position when window is not visible.

Fixes #4561
RTS: Optimize alpha mask creation. Over 5 times faster than before for
inversed subtitles.
Translations: Fix a rebase error.

Fixes #4564