fix the first file in a zip is a directory will raise error in zipContentExt
fix typo
This should fix #785.
fix scaleByDPI(1) returns 0 in screen of lower DPI
enable highlight in dictionary lookup window
This should fix #774.
move 'Set defaults' to tools tab
And save to persistent defaults dialog will popup when holding
on the 'Set defaults' menu.
Merge pull request #786 from chrox/master

enable highlight in dictionary lookup window