Introduces validToImportAsProperty, which has to perform extra
checking the make sure that a get/set pair are compatible with import
as a property. This includes matching up 'self' parameters, matching
get's return type with the set's argument type, etc. Includes more
extensive tests.
Expands support for inference of computed properties, whether instance
or static, to include get-only. Adds test cases for both inference and
manual annotation for static computed properties.
Introduces import-as-member (IAM) inferene system, to automatically
infer details that would otherwise have to be manually specified with
the swift_name attribute.
Basic functionality present, though there are some issues with
properties at the moment. No hooks, options, or tests yet, stay tuned.
