fixes 'exec() call to unknown plugin' on android
android platform is now compatible with cordova 3.0.x
it's plugins.ChildBrowser not plugins.childBrowser
added copyright
fixed callback issues
webview methods should be called within same thread
fixes ERROR: Method 'close:' not defined in Plugin
added copyright note
Merge branch 'master' of https://github.com/everplays/ChildBrowser into everplays-master