added a command-line option to override the mods defined in SoundRTS.ini

For example: soundrts.py --mods=soundpack,orc
Windows installer: added shortcuts to some mods including CrazyMod 8.2
added parameters/recommended_maps to style.txt

This way a mod can force its recommended maps to the top of the map menu.
bug fixed: on the Mac, the game couldn't start

Getting the system language while running from the terminal caused an error: “ValueError: unknown locale: UTF-8".
Note: if the error happens, the game will use English by default and advise the user to edit cfg/languages.txt.
refactoring: extracted campaign.py from game.py
refactoring: simplified the code in the server menu for alliances
cleaning: removed some obsolete, commented out code
added races menu to single player training
in map selection menus, the previously chosen map will be selected by default
extracted the units guide from the main manual
fixed: removed obsolete instructions about "streaming sounds" from the map making guide
map making: in "intro", "cut_scene" or "sequence", a number in a sequence can now also represent a text message defined in tts.txt
campaign cut scenes: replaced the recorded speech with text
smarter target selection with Tab

It now selects in the following order: resources, then damaged buildings, then free space, then exits (if in the current square). If the current order is to build something, it selects free space first.
manual: rewrote the chapter about starting a server
bug fixed: in cheat mode, map navigation in previously unknown places would never cause collisions
modding: made sure that a building can leave a meadow and turn into a unit, and that a unit can turn into a building if a meadow is available

(added "flyingtownhall" as an example mod)