WIP, switching to new branch to decouple project builder from owa downloader
Baby steps refactoring
Refactor to further decouple apk_project_builder

* extract loader
* extract project build dir
* code style cleanup
Merge pull request #23 from mozilla/decouple-project-builder

Decouple project builder
Merge branch 'master' into apk-metadata

Conflicts:
	lib/owa_downloader.js
Hooked up metadata API. Implemented much of Issue #15