UFO:AI/trunk, rev. 39

Derived another heuristic for approximating UV texture mapping with .map mapping; this new algorithm is optimal in some (rather artificial) sense, does a lot better when exact conversion is not possible, but is also a lot slower compared to the old method. Coded a general profiling decorator that should be useful for other projects too (in its simplest one may just say @profile before a function, but it can take some arguments and even simulate count of positional arguments of the original function to work around some code that checks it). Fixed exporting attributes with double quotes and made a quick patch fixing grouped objects not appearing on exported maps.