Made artnames an array, for easier manipulation
Actually open the browser the first time we export the project
Fixes a bug with artboards, where their dimensions and positions are wrong if they contain layers with effects (this is probably not 100% right, but I can't find another way to explain it :)
We may not be perfect, but we're not a draft anymore :)
Ignore MSPage objects when exporting
Huge refactoring to improve compatibility with Sketch 3.0 while keeping backwards compatibility with Sketch 2.x. Closes #36

For everyone: please report all bugs you find as a consequence of this (I've fixed some existing bugs, but I'm sure there are more hidden there, somewhere)

For @jmwhittaker: hope this works for you, let me know if it doesn't :)
Added example document for Sketch 3.0