Add link to presentation slides
Add Foundation for headers, NSObject requires it
Merge pull request #3 from skabbes/fix/import_foundation

Add Foundation for headers, NSObject requires it
Clarify @import doc in README.md
Forward-declare interface crossreferences. Fixes #4
Use std::experimental::optional in the test suite.
Naming fixes: switch towards Proxy instead of Wrapper
Fully-qualify JNI class names