remove undocumented getStepByBuild

Its functionality is more naturally handled in getStep.
Use the Data API for build requests

This also renames the test case for the build request distributor.
update README.md with remaining buildrequest tasks
tests for PerlModuleTest
Rewrite PerModuletest to use a LogObserver
make test logfiles act more like real wrt newlines
refactor DebLintian and RpmLint to use a LogObserver
remove log.readlines
Merge branch '9/remove-getStepByBuild' of git://github.com/djmitche/buildbot into nine
Merge branch '9/use-br-data' of git://github.com/djmitche/buildbot into nine
Merge branch '9/use-data-api-5' of git://github.com/djmitche/buildbot into nine

+autopep8, pyflakes
Fix few bugs on the UI:

- fix karma watch mode
- Fix number vs buildid bug in the build page
- python: add events for new logs
- Fix race condition between event registering and first value got from data api
- fix logviewer so that it does not poll anymore