Godot 3.1 Support

This release has 3.1 support. There are still a lot of bugs, but at least this works with 3.1.

Configurability and Performance

Adds configuration options like custom godot binary, path to iOS deploy tool, logger level and file, debug collision and navigation flags, open or copy path to generated Xcode project, and fill in export presets with team id and provision id.

Additionally, more operations are async which removes the stutter when pressing buttons.

Next up, multi-platform support!

First Community Release

First release. Working, but sharp around the edges.