Bump to 2.8.0~pre6
Improvements to `form_base`
- Convert to new-style plug-in API
- All strings to unicode
- Respect `focus=no` (#208)
Update offline-help pages
Fix filepool help button and unicodify filepool source
Fix typo in mouse_response
Improved module loading
- Always print stacktrace when plug-in fails to load, not just in debug mode
- Use `imp` style module importing, and not `exec()`
Where possible, replace `exec()` and `eval()` style code by cleaner `getattr()` and `__import__()` statements
Fix regression in form_base
Respect `experiment_path` when loading experiment from string
Do not crash on missing  while loading plug-ins
Merge remote-tracking branch 'origin/playground' into playground
Add markdown to setup-win32.py
Update debian/changelog