* [bindings-generator] Improve build & project file.
* Add missing [MarshalDirective] attributes.
Add missing [MarshalDirective] attributes, which also requires implementing
support for out parameters in the binding generator, since one of the
signatures missing the [MarshalDirective] contains such an out parameter.
Also add tests for all the API I've added [MarshalDirective] to.
* [bindings-generator] Remove redundant if check.
* [monotouch-test] Rename file to end with 'Test.cs'.
* [tests] Fix a few build errors for Xamarin.Mac.