* cleaned up code and improved coding style
* removed old SINGLE_SOURCE_COMPILE macro relicts
* use QString::toUtf8() instead of QString::toAscii() wherever possible
Added createMimeData() method to StringPairDrag which creates a proper
QMimeData object for StringPairDrag. External code can use it to create
a QMimeData object which can be received by users of StringPairDrag.
Signed-off-by: Tobias Doerffel <tobias.doerffel@gmail.com>