exit application via QCoreApplication::exit now
Update version to 3.1.7.
remove QtWebKit build dependency

    it is never used in the project
Merge pull request #222 from Chilledheart/patch-2

exit application via QCoreApplication::exit now
Merge pull request #223 from Chilledheart/patch-3

remove QtWebKit build dependency
Merge pull request #2 from haiwen/master

up