Extended Mail features

[svenoe]

Allow pasting of several mail addresses, and provide small buttons to move addresses between to, cc and bcc.

[svenoe]

Implemented - should be beautified at one point, probably preparing small svg icons is the best solution. The rendering differs largely between browsers and even between the places where the current texts icons are located. (Partly due to different interpretation of fractional pixels, but without that, it's a mess, too...)