v0.12.0

• Generation performance improved from 20-65% on large packages (more improvement on packages with lower usage of comment references and complex inheritance chains, like angular2).
• Improvements to warnings, including indicating referring elements where possible. #1405
• Enable support for generic function types. #1321
• Update analyzer to 0.30. #1403
• Enhancements to css style to better match dartlang.org. #1372