get number of cpu, using multiple concurrent job processes;
issue #2789: Adds Map, Dictionary perf test, not yet finished.
Removes unused cast in CCTMXTiledMap.cpp.
issue #2789: Improves performance for Map<K,V>::keys.
issue #2789: Adds performance test for Map<K, V> and Dictionary.
Merge pull request #5127 from dumganhar/iss2789-perf-container

issue #2789: Adds performance test for Map<K, V> and Dictionary.
Merge pull request #5126 from liang8305/use_multiple_build_process

get number of cpu, using multiple concurrent job processes;
closed #2789: Adds a macro ‘’USE_STD_UNORDERED_MAP” for switching the implementation of Map<K, V> between using std::unordered_map and std::map.
Merge pull request #5128 from dumganhar/iss2789-perf-container

closed #2789: Adds a macro ‘’USE_STD_UNORDERED_MAP” for switching the implementation of Map<K, V> between using std::unordered_map and std::map.
Update CHANGELOG [ci skip]
Merge pull request #2 from cocos2d/develop

Merge parent