getInstance() / destroyInstance() are used...

... instead of sharedXXX / purgeXXX.
They are more C++ friendly, and also easier to remember.

common files + Mac files + iOS files + tests/samples files were updated.

The old methods are deprecated now.
issue #2397: Director::sharedDirector --> Director::getInstance() for all files.
issue #2397: FileUtils::sharedFileUtils --> FileUtils::getInstance() for all platforms
issue #2397: Updating cocos2d.ini and CCFIleUtils.pkg.
issue #2397: EGLView::sharedOpenGLView() --> EGLView::getInstance()
issue #2397: Shader::sharedShaderCache() --> Shader::getInstance().
issue #2397: Updating bindings configuration. [Lua and JS].
issue #2397: sharedAnimationCache --> getInstance.
issue #2397: Updating CCAnimationCache.pkg
issue #2397: sharedSpriteFrameCache --> getInstance, purgeSharedSpriteFrameCache --> destroyInstance.
issue #2397: sharedNotificationCenter --> getInstance
issue #2397: UserDefault::sharedUserDefault() --> UserDefault::getInstance(), UserDefault::purgeSharedUserDefault() --> UserDefault::destroyInstance();
issue #2397: CCTextureCache:sharedTextureCache --> CCTextureCache:getInstance.
issue #2397: FileUtils::sharedFileUtils() is not needed to be defined in CCFileUtilsXXX.cpp
issue #2397: Typo fix.
issue #2397: Updating CCUserDefaultAndroid.cpp.
issue #2397: Updating CCUserDefaultAndroid.cpp.
issue #2397: Updating Lua bindings.
[ci skip] Reverting cocos2dx/platform/android/java/project.properties.
Merge pull request #3139 from dumganhar/iss2397-getInstance

Merge PR https://github.com/cocos2d/cocos2d-x/pull/3136