Fixing a usuability issue where clicking 'escape' would shutdown the game with the Options menu open.
Use semantic -mdoc macros for the manpage.
Refreshed a bit the doc in the manpage.
While seeing it, tweaked the readme.md a bit.
Corresponding tweak in the Readme simple text file
Typo fix in end credits.

Thanks to Nemesis for spotting that one. :)
Russian translation fix by dimproject.
Incorporating the precompiled header into the map editor build.