Closes #96.

Changes proposed in this pull request:

• add a function window.getWritableDir that returns a Promise -> a writable dir, either next to an executable or in the home directory;
• make exporter, project manager, PC exporter work with this function so that they are less platform-dependent.
• fix drawing issues on macs with no graphics acceleration available.
• pulls the docs so that a build can be made,
• also removes google closure compiler :/