I tried to fix two issues here:
1) The recently opened urls where not saved
2) Semms that in KUrlRequester's open dialog you could only select files and not folders. You could stil select folders by typing their name in in text area of KUrlRequester but not through the dialog. So I just added appropriate buttons to open a QFileDialog in which you could select either folders or folders dependinf on the clicked button.
PS: Seems that there is not much activity in the project and I wasn't sure who I should add for reviewing, so I just added the last two committers in git :)