[Azoth] Command_f now takes the message by non-const ref.

Allows modifying it.
[Azoth Keeso] Removed unused regexps.
[Azoth Keeso] Use IProvideCommands instead of hooks.
[Azoth SHX] Use IProvideCommands instead of hooks.
[Xtazy] Qt5 compatibility.
[Azoth Xtazy] Don't support disabling /np.
[Azoth Xtazy] Use IProvideCommands.
[Monocle] ISupportPainting::PaintPage() takes scale now.
[Monocle PDF] Implement ISupportPainting.
[Monocle] Use highres printer.
[Monocle] Use ISupportPainting during printing if available.
[Monocle PDF] Fallback to Arthur backend in PaintPage.