Convert pygtk to pygi/GTK3

[Doadin]

Basicly pygtk has long been depricated and there now exists and has for a while new pygi setups for windows makeing it easy just as it was before to get a windows build environment setup.(In the past there was a time where it wasnt easy to work with pygi on windows). As a part of moving forward (posibly to python3 i know theres a ticket for that) It is recommended to convert first then work on python 3. I know we are still waiting on other utilities like twisted to update for python3 but this is just a good idea either way. At this time me and bendikro both have made efforts to make this conversion. The collection of which can be seen on my github repo here: ​https://github.com/doadin/deluge/tree/develop-pygi . It still has alot of work but its a start.

[Doadin]

Current Branch:https://github.com/doadin/deluge/tree/develop-convert_to_pygi_gtk3 Issues: 1.Compatibility with older GTK versions

• Errors in Files tab progress
• Errors in peers tab

2.Issue with autoadd label option in the autoadd plugin not storing the selected label.(after adding hitting edit the label combobox is empty) Though clicking the combobox still gives options.