Viewport: fix class documentation
Wrap ChamplainKineticScrollView

	* champlain/champlainmm.h: Add kinetic-scroll-view.h.
	* champlain/champlainmm/.gitignore: Ignore
	kinetic-scroll-view.*.
	* champlain/src/champlain_signals.defs: Add "panning-completed"
	signal; add "mode", "decel-rate", and "motion-buffer"
	properties.
	* champlain/src/filelist.am: Add kinetic-scroll-view.hg.
	* champlain/src/kinetic-scroll-view.[hg|ccg]: New files.
	* tools/extradefs/generate_extra_defs_libchamplain.cc: Add
	CHAMPLAIN_TYPE_KINETIC_SCROLL_VIEW, and include specific header.
	* tools/m4/convert_libchamplain.m4: Add conversion from 'const
	Glib::RefPtr<Viewport>&' to 'ChamplainViewport*'.