Graphical user interface landed

Finally after several years of development a graphical user interface landed. It's far form complete but ready for a first review.

Unlike the other graphical sieve editors, it works like a visual code generator. It abstracts syntax and basic grammar, but does not touch or limit the logic. It's possible edit complex scripts with arbitrarily nested if statements.

To access the new interface toggle in the script editor the new "view source" toobar button.

The new interface fully relies on a drag&drop paradigm. To create Elements just drag them from the sidebar and drop it a the desired position. Deleting is even more simple. Drag the element into the trash, and it's gone including all nested elements. In order to move elements drag them, indicators will guide you where it's safe to drop. To edit an element just click on it.

Until now the interface supports the Sieve commands from Sieve (RFC5228), Imap4Flags (RFC5232) and Reject (RFC5429). Others like body and date until now not implemented. The development focus is currently the user interface. It's fully functional but needs lots of polishing in order to look nice. So there is still much work left and helping hands are welcome.

Feedback is also welcome. Just post it to the mailinglist sieve(at)mozdev.org or directly to me schmid-thomas(at)gmx.net