Fixing 2 memory leaks with double-checked locking, only a few scripts
uses timers and start conditions.
Fixing 3 memory leaks with initial default capacity, maps and list were
initialized with a default capacity, when this maps will only hold 1 or
2 entries/elements.
Renaming start condition related methods to make them easier to find
while typing quests.
Added missing JavaDocs.

Reviewed by: @Sdw-