Finish modifying analysis server to make use of code generation.

Generated code is used to produce the response to these requests:
- analysis.updateOptions
- analysis.updateContent
- analysis.setSubscriptions
- analysis.setPriorityFiles
- analysis.setAnalysisRoots
- server.shutdown
- server.setSubscriptions

Generated code is used to produce these requests:
- server.shutdown
- server.getVersion
- server.shutdown
- server.connected

Generated code is used to produce these notifications:
- completion.results
- analysis.overrides
- analysis.outline
- analysis.occurrences

Generated code is used to decode these notifications:
- server.status

In addition, some dead code was removed, the 'protocol.dart' and
'protocol2.dart' files were combined, and the fields Response.result,
Request.params, and Notification.params were made private (to
encourage future use of the generated code).  Also, some overly
verbose import statements were cleaned up by using "hide" rather than
"show".

R=danrubel@google.com

Review URL: https://codereview.chromium.org//506433002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@39516 260f80e4-7a28-3924-810f-c04153c831b5