tool/fix_include_ifndef: consider license header
Move nitpicker_gfx/geometry.h to util/geometry.h

This patch makes nitpicker's geometry utilities available for the use
by other programs. Thereby, the 'Point', 'Area', and 'Rect' classes
have become templates that take the coordinate type and distance type
as arguments.
Add demo/include/util/dither_matrix.h

This patch moves a repeatedly used dithering matrix from the scout
source code to a public header to share it across programs.
Remove nitpicker_gfx/miscmath.h
Move nitpicker_gfx/color.h to util/color.h
Remove nitpicker_gfx/nitpicker_types.h
Generalization of nitpicker's graphics backend

This patch re-arranges nitpicker's graphics backend in a more modular
and expandable way. Generalized versions of the 'Canvas',
'Chunky_canvas', and 'Pixel_*' classes have been moved to
'os/include/util/' and 'os/include/os'. The only remaining parts that
are specific to nitpicker's needs are a few drawing functions, each
located in a distinct header at 'os/include/nitpicker_gfx/'.
Clean up scout widgets

This patch integrate the scout widgets with Genode's new API headers
'util/geometry.h', 'os/surface.h' and 'os/texture.h'. Thereby, we get
almost rid of the platform-abstraction shim that was never used anyway.

Furthermore, it extracts the parts that are worth reusing from the
scout implementation to the public location 'demo/include/scout'.
scout: replace x,y,w,h with Point and Area
scout cleanup (more x,y -> point)
scout: fixup (find(x, y) -> find(Point)
scout fixup