fix cannot highlight hyphenated words in crereader
add bold property for text rendering
make dictionary title, toggle option and button text bold
loading KoptInterface only in pdf and djvu reader
This will save 4MB RAM in crereader which otherwise will load
liblept.so.3 and libk2pdfopt.so.2 automatically for nothing.
Merge pull request #486 from chrox/master

fix cannot highlight hyphenated words in crereader