Superpaper

This is a fix release, changes include:

- Fix Command Line Interface, which was broken due to threading changes made for v1.1
- Fix dbus module import for KDE in the pre-packaged version
- Warn about wx module import failure in script mode
- Handle empty DESKTOP_SESSION env variable, attempt to use feh by default in this case
- Tested to be working on LXQt
- Code cleanup.

Minor update:
Linux package was updated to fix a KDE specific issue.

New in this release:

- GUI
- Wallpaper profile configuration
- General settings
- Error dialogs/messages and hopefully more robust error handling in general
- Help dialog
- Linux binary, no more hassle with dependencies
- Alignment test tool designed to help with dialing in all the settings
- Performance
- Better threading for heavier tasks
- Misc.:
- Fix URL in about dialog
- Fix for CLI offset handling
- Fix monitor sorting issue when using alignment corrections if display order detected badly
- Logging fix, attempt to better log uncaught exceptions
- File handling fixes: handle empty folders and non-image types
- Windows: handle Windows's negative offsets correctly

Initial release of Superpaper with features as described in the readme.

Currently building executables is only working on Windows so this release has portable packages with an EXE for Windows and another package with the script (.pyw), which is cross-platform.

Aside from Cinnamon and Windows 10 testing has been carried out in virtual machines so behavior on real machines is unknown, though potentially in the direction of fewer issues given that simulation of multiple monitors on VirtualBox is less than perfect.