Fixed bugs for Editor
fix box2d dynamic tree draws
fix some box2d test position
fixed bugs
add background.wav to wp8 to play
ccvector_to_luaval would lead to memory leak because call  the `retain`
Merge branch 'develop' of https://github.com/cocos2d/cocos2d-x into develop_socket
add box2dbed test keyboard event.
delete Time of Impact test which can not shown
Merge pull request #6064 from samuele3hu/develop_socket

ccvector_to_luaval would lead to memory leak because call the `retain`
Merge pull request #6065 from boyu0/3.0rc1_test

fix box2dbed dynamic tree test draw.
Merge pull request #6063 from koowolf/add_bg_wav

add background.wav to wp8 to play
fixed logical error in Label::updateFont.
Merge pull request #6052 from pipu/develop_pipu_fixedbugsforeditor_1301

Fixed bugs for Editor
fixed logical error.
fixed logical error in Label::create.
Merge pull request #6067 from Dhilan007/develop_label

1) fixed logical error in Label::updateFont.
2) fixed the font file searching strategy, used FileUtils::isFileExist to check whether the font file exist rather than find . letter.