Unicode-related fixes to plugin framework ad joystick plugin
Bump to 2.8.2~pre2
Check extension when opening file
Allow opening experiments by dropping onto overview area
Give notice on variably defined or invalid combobox entries in plugins
Add fallback pool folder to facilitate versioning
Fix regression when opening file
Update debian/changelog
Make sure that text is unicode before applying bidi (closes #253)
Allow margins, spacing, and theme to be set in `form_multiple_choice` plug-in (closes #255)
Bump to 2.8.2~pre3 and update debian/changelog