[closes #87, closes #25] Refactored update() to now return whether the given setup led to a legal board position or not. Removed getState(), use the result of the update() call instead. The game also does not have an invalid-state anymore, although while_capturing and placing_handicap was still needed.
Updated comment regarding handicap in the GoRules parameter.
Fixed bug concerning capturing. (returned before assigning to variable...)
Another typo m(. Also: copy-pasting ftw!
Merge remote-tracking branch 'remotes/origin/#87_backend_refactoring' into #81_Virtual_GoGame

Conflicts:
	Go_Backend_Unittest/backend_test.cpp
[refs #87] fixed faulty unit test