Merge branch 'develop' of https://github.com/cocos2d/cocos2d-x into develop

Conflicts:
	plugin/samples/HelloSocial/proj.ios/HelloSocial.xcodeproj/project.pbxproj
Add C++ 11 support for iOS projects.
Resolve the bug in the reflection of plugin.
Modify the license of plugin twitter.
Delete the developer ID in project config.
Merge pull request #2846 from natural-law/master

Add twitter plugin for iOS
Merge pull request #2847 from natural-law/develop

Add twitter plugin for iOS
[win32] Updating TestLua.
Merge pull request #2848 from dumganhar/master

[win32] Updating TestLua.
[jsoncpp] Value::null -> Value::jsonNull to avoid conflict when compiling with clang++ or high version of gcc since null is defined as a key word.
[Tizen] Updating project configurations.
Merge pull request #2849 from dumganhar/master

[Tizen] Updating project configurations.
[Win32] Updating project dependence.
check if delegate is not null when dispatching keyboard event
issue #2271: Fixing some memory leaks.
[VS2012] Warning fixes.
CCScriptEngineManager::sharedManager()->purgeSharedManager(); --> CCScriptEngineManager::purgeSharedManager();
Merge pull request #2851 from dumganhar/master

issue #2271: Fixing some memory leaks. [VS2012] Updating project dependence and warning fixes.
Updating JS-Test.
Merge pull request #2852 from dumganhar/master

Updating JS-Test.