WINTERMUTE: Fixed typo in base/scriptables/script_ext_string.cpp

Changed call to strlcpy to Common::strlcpy.
The former wouldn't compile in VS2012 and possibly other compilers.
WINTERMUTE: Fix rotation offset

Fix sprite rotation so that zooming and rotation (either around an
arbitrary point  or around 0,0) behave in a consistent fashion.
This still does not support interpolation and there is a 1px offset
popping up here and there, probably due to a rounding error.