Basic support for source maps

Automatic source map generation and optional source map annotation
appending to the end of compile file. You can enable it with
createSourceMap and appendSourceMappingURL options as follows:

app:
    options:
	namespace: 'app.start'
	outputFilePath: 'client/app/build/app.js'
	createSourceMap: yes
	appendSourceMappingURL: yes
Merge pull request #10 from isnotgood/master

Basic support for source maps