api 6.x-1.4-beta1

Changes since version 6.x-1.3 (which was released November 22, 2010):
- Overhaul of the between-branch navigation on function, constant, etc. pages, for better clarity and so it would work for functions that moved to different files between branches. Issue: #770784: Replace branch local tasks with our own theme function.
- Handle the case of duplicate function names better (e.g. db_query(), which exists in two places in the Drupal 6 source code). This involved changing the URLs of pages to include the file name. Issue: #179062: handle duplicate function names
- Updates for compatibility with new versions of the Grammar Parser module.
- New feature: drush command to list branches.
- New feature: ability to parse *.test files in source code.
- New feature: 404 pages redirect to a search.
- Numerous other bug fixes and documentation tweaks (check the issue queue).