Merge pull request #9 from kozec/gtk3.10

Merged stuff for GTK3.10 (Fedora 20) compatibility. Fixes #7
Fix: get back paned handle margin that suddednly disappeared in Gtk 3.14
Fix: Force font color on forced background. Fixes #11
-a option, shows about dialog and exits
Fix: AboutDialog: dialog.show_all() shows redundant Credit and License buttons created under unknonw circumstances. Fixes #10
Merged Windows port and 1st run wizard code from branch
Merged Windows stuff from branch
Typo
Dont' offer desktop notification settings if there is no support for it
Default configuration for windows