HTML version not working

[Arcnor]

I've done a little work to make the HTML version compile. This needs #45 to be merged in first, or the changes you'll see here will be very polluted. What is missing/should be done:

• Pattern and Matcher are not supported, so they need to be replaced on BitmapTextMultiline and Window
• String.format and String.toUppercase(Locale) are not supported. If we don't mind waiting, this will be fixed by I18N support #43 because it replaces all those calls with LibGDX's I18N support
• InterlevelScene and WndRanking are creating a Thread to do stuff, but that's not supported on GWT. An alternative might be using Web Workers or something similar from GWT, but we'll need to abstract the piece of code that does the work so we can call GWT classes on the html module.
• Bundle uses the org.json package, so we should either add the package sources so it can be compiled by GWT, or replace that package with LibGDX JSON support that is multiplatform.

[gnojus]

Just FYI, https://gnojus.github.io/pixel-dungeon-gdx is a fork with working Web/Html version