Fix httpdomain compatibility issue with Python 2.6
Fix release version generation for docs.

The logic:
- If you didn't run ./bootstrap the version will be X.Y.Z-dev
- If you did: X.Y.Z+build.hash
- For CouchDB releases - just X.Y.Z (because we remove STAGE/RELEASE
  info from acinclude.m4.in)
Add missed docs files for `make html` output.