New QTodo logo as proposed in #79

More contemporary and 'easy' look. 
Drops the .txt for better legibility, puts the stress on the Q and the V-mark.

The original file was created in Vectorworks 2013, exported to PDF and saved as PNGs in Photoshop. The icon file is created from the 48, 32 and 16px PNGs with XnViewMP.