Added AboutWidget
                                                                        |
Added AboutWidget to the left hand tree on the config tool. This
widget is based off the previous AboutDialog. It contains information
about Freeseer, including copyright and version. There are also two
buttons, one links the user to the freeseer github io page for help and
the other lets them report an issue on github.

The AboutDialog has also been modified. Essentially it was converted
to a widget (AboutWidget), which is used now for both AboutDialog and
the config tool.

Related to #411