Demo version of koptreader config dialog.
add config options
first usable koptreader for new UI
make pdfreader and djvureader the defaults
larger option text in paperwhite
save/restore koptconfig to setting files
use koptinterface to reflow text in pdf/djvu readers
Merge pull request #684 from chrox/koptreader-new-ui

add reflow mode in pdf/djvu readers