graphical interface refactoring: added two properties in style.txt

"shape": "square" or "circle" (default)
"color": color name (by default a custom color is computed from the object's title)
first version of units blocking an exit

Now "block" is the default action when the target is an exit.
A unit won't move as long as it is blocking an exit.
A unit acts as a gate: it lets other units move if there is no enemy around.
At the moment one unit is enough to block any exit.
updated Russian translation

thanks to Kvark
any building type can be built on an unblocked exit

Note: now a building or a resource stores the land it uses in order to restore it eventually.
removed unused sub-square code
now walls and gates are just buildings
bug fixed: fleeing units would retaliate to attacks
replaced every occurrence of "race" with "faction"
bug fixed: units in the splash damage area wouldn't be affected if their distance from the attacker is bigger than basic range

(closes #39)
renamed CrazyMod8.2.bat to CrazyMod.bat
modding: don't issue a warning if "color" or "shape" is missing
added diagonal squares to the current neighboring squares

(closes #34)