gobject-introspection for Crystal

This is closer to a proof of concept, than to something real world usable. If you want to turn it into something usable, feel free to do so. If you want to hack on it and make some generally useful progress, pull requests are welcome!

State & Wishlist

• Generates bindings that parse, but are probably not complete or bug free.
• Generates bindings for gobject-introspection that are useable by the glue & generation code that generates them.
• Generates bindings and wrappers for Gtk that, together with some hand-written glue code can show a blank window and load a glade file.
• Generates not only the lib code, but also the boilerplate for the glue code (WIP, not complete)
• Should figure out dependencies the smart way, that is only generate bindings for dependencies that are actually used in the binding.
• Should figure out link flags for when gi_repository_get_shared_library return NULL, or at least not crash on that.
• Should have a nice command line interface
• Decide whether/what generated bindings to keep in this shard and what to move into its own shard (Gtk probably).