Added frontend/configtool related unit testing and refactoring improvements

[SRomansky]

This pull requests aims to address the outstanding TODOs inside of the frontend configtool related classes

Related #484

[SRomansky]

I am not really sure why, but trying to test the reset button on the config tool's general settings tab causes a seg fault. For instance, self.config_tool.confirm_reset() or even using a mouse button click will seg fault the application.

[zxiiro]

Does the config tool confirm button open a popup window?

If so the segfault is probably caused by the same issue as in this discussion: https://github.com/Freeseer/freeseer/pull/631#discussion-diff-19700177

[SRomansky]

Yeah, @zxiiro

        confirm = QMessageBox.question(self,
                                       self.confirmResetDefaultsTitleString,
                                       self.confirmResetDefaultsQuestionString,
                                       QMessageBox.Reset | QMessageBox.Cancel,
                                       QMessageBox.Cancel)

Is created to confirm that a user did mean to reset their configuration. I think this is the same as what you noted here - https://github.com/Freeseer/freeseer/pull/631#discussion_r19700925

[SRomansky]

I have put in a fixme.

[dideler]

Thanks @wigglier. If you squash your commits then this will be ready to merge.

[SRomansky]

@dideler, should be good to go.

[dideler]

Thanks for the tests, Stephen.

If you're interested in continuing work on Freeseer, just let us know and we can add you as a committer.

[zxiiro]

Thanks for working on this during the holidays. Have a great New Years.

[SRomansky]

Have a good holiday too @dideler, @zxiiro