Add 'tag' Jake task.
Source comments.
Refactor module exports.
Fix default API htmlReplacement option value.
- Implemented a common definitions.d.ts file containing common reference directives.
- Renamed exportCommonjs() helper.
- Source header comments.
Renamed common references file.
JakeFile: Simplify source files array  generation.
Sensible hand-written rimu.d.ts definitions file (previously compiler generated with API plus lots of non-API declarations).