Optimize the implementation of download binary files.
Support generate release apk with prebuilt libs.
Merge pull request #113 from natural-law/support-prebuilt

Support generate release apk with prebuilt libs.
Support skip ndk-build when the value of parameter --ndk-mode is none.
Merge pull request #114 from natural-law/develop

Support skip ndk-build when the value of parameter --ndk-mode is none.
Update the version of the binary files.
Merge pull request #115 from natural-law/develop

Update the version of the binary files.
Support custom steps during console compile.
Merge pull request #116 from natural-law/develop

Support custom steps during console compile.
Fixed #5354: Specify js version to ECMASCRIPT5 in build.xml for google closure