Removed delete from CC_SAFE_DELETE and changed 0 to nullptr on all CC_SAFE macros

This implements this issue: https://github.com/cocos2d/cocos2d-x/issues/3099

I've also change all pointer assignments to 0 to assignments to nullptr on the CC_SAFE macros.
Also aligned them for better readability :)
issue #2345: refract CCImage and CCTexture2D.
issue #2345: move g_texturePixelFormatInfoTables into Texture2D
issue #2345: update the png, jpeg and tiff libraries. Fix the testFormatForPvrTCSupport return incorrect answer when GL_COMPRESSED_RGB_PVRTC_2BPPV1_IMG undefined.
issue #2345: Merge branch '2345' into iss2345_refactor_ccimage
issue #2345: edit linux command to link the libpng12-dev.lib instead of use ourselves. Move ccTexParams into CCTexture2D
issue #2345: delete the linux png libraries.
Merge branch 'develop' of https://github.com/cocos2d/cocos2d-x into iss2345_refactor_ccimage
issue #2345: fix some coding style
issue #2483: Upgrading spidermonkey library to v23 for all supported platforms.
issue #2483: The callback type of 'delete' property has been changed from 'JS_PropertyStub' to 'JS_DeletePropertyStub' in v23.
fix js and linux compile error
add missing in ReadMe.md
issue #2345: edit getPixelFormatInfoMap method to return reference.
fix some format in ReadMe.md
issue #2345: fix mac crash due to libjpeg
Merge pull request #3384 from minggo/improved_readme

Improved readme
[Android] Updating launch activity name.  ".TestJavascipt" --> "android.app.NativeActitiy" for TestJavascript project.
issue #2345: update generated index
issue #2345: edit for linux compile error