JsCode parser: GWT parser copied
JsCode parser: renamed imports of gwt ast to dart ast
JsCode parser: removed GWT source info usage
JsCode parser: fixed expression statement stackoverflow error
JsCode parser: added NUMBER literal types

Splitted NUMBER literal type into NUMBER_INT and NUMBER_DOUBLE
JsCode parser: added insideFunction flag
JsCode parser: moved rhino parser to separate module
JsCode parser: removed magic string
JsCode parser: literals creation
JsCode parser: removed commented out code (source info usage)
JsCode parser: auto reformatted code
JsCode parser: made methods static where possible
JsCode parser: renamed sourceNameStub to comply with a codestyle (UPPERCASE)
JsCode: added test cases
JsCode: added jsCode declaration
JsCode: jsCode expansion at translator
JsCode: language injection