Container is only used to add elements, iterate over all of them and
clear. Multimap adds overhead for all of these operations without any
benefits. Reduce Animation::resetActiveGroups CPU time usage by 50%.
Kept some fixes from the first round of review. Found out that several
targets weren't being built with the same basic warnings disabled.
Disabled a few warnings for external libraries specifically, rather than
applying them to all targets.
Most warnings are innocuous (wrong type-specifier for forward
declarations, conversion of literals into unsigned integers, warnings
about methods optimized out), but I believe actual bugs were revealed in
vartypedelegate.cpp and combat.cpp.
