Gtk UI: Import titles from OPML / directory (bug 1711)

We now prefer titles from the podcast directory and OPML
files to the title in the feed. For URL-only adds, we still
use the title from the feed.
Remove old api.py module
Gtk UI: Integrate shownotes into main window

For now, this removes Flattr integration, but I'm sure
Bernd will fix this sooner or later.
Merge pull request #28 from brot/remove-api

Remove old api.py module
YouTube: Remove dependency on OrderedDict

We still need to support Python 2.6 easily, as this is
what we have on MeeGo 1.2 Harmattan.
Gtk UI: Don't require Gtk+ 2.24 in .ui file
Vimeo: Fix downloading of Vimeo videos
YouTube: Fix downloading on Harmattan
Util: Python 2.6 compatibility fix
QML UI: Cleanup / simplify UI
Pipe: Experimental pipe-based IPC interface
Pipe module: Minor bugfix
Fixing TEDtalks subtitle downloader

the introDuration parameter on tedtalks page has changed a little, now the
parameter appears using htmlentities, so I had to change the split for it to be
able to find the subtitles.
Also now the subtitles appears in seconds.
And I've provided 15 as a default value, since it's a good guess for modern
tedtalks (older ones have longer introductions)
Vacuum minidb-based databases too (bug 1721)
Pipe: Avoid downloading podcast cover art
Merge pull request #30 from daneoshiga/ted_subtitles_fix

Fixing TEDtalks subtitle downloader
Improvements to the extension system

- Add category metadata in every extension
- Show this category in the extension list gui
- Add "mandatory_in" and "disable-in" configuration for an extension
- Add Ubuntu unity check to enable/disable unity specific extensions
- Move "gpodder.win32" and "gpodder.osx" setting to the "gpodder.ui" namespace to be able to use it in the extensions category settings
- Only show metadata information in the right-click dialog of an extension
Dont warn about system files in windows (bug 1712)
Merge pull request #29 from brot/master

Improvements to the extension system
Merge pull request #31 from smunkel/master

Dont warn about unknown file if it is a system file (Bug 1712)