Add two profile options for the copy & paste behavior of mouse

* support "automatially copy selected text into clipboard"
* mouse middle button can be customized to paste from selectio or
clipboard

The first feature might look like a unnecessary duplicate of the
"synchronize selection and clipboard" feature of Klipper. However, that
klipper feature is generally problematic, while doing it only in Konsole
is generally useful and harmless.


FIXED-IN: 4.9.0
REVIEW: 103861
DIGEST: