Use zinc analysis results for dependency analysis.

- Add a new build product type, "ivy_jar_products", which is produced
  by IvyResolve, and stores processed Ivy reports in the build products,
  indexed by configuration.
- Modify scala_compile to invoke zinc with a flag that makes it
  generate text versions of the analysis cache files, which can be
  used by dependency analysis.
- Rewrite dependency analysis to use the zinc analysis data to specify
  dependencies instead of parsing class files and other build products.

Auditors: benjy
Applied review changes.

- Got rid of old, un-needed code.
Bump the required version of zinc.