Log Message:
Update to 0.8:

Devil's Pie "Mystery Boxes" 0.8
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* Bring back --apply-to-existing, so you can work on existing windows
* Add maximized_horizontally and _vertically to the resize action (John Russell)
* Add an execute action (John Russell)
* Add an opacity setting action (Guido Boehm)
* Generate decent matcher/action documentation at build-time from the source
* Check that regular expressions parsed correctly, fixing a common bug
* Less compile warnings