This patch improves the `Text_painter` utility that is commonly used by
native Genode components to render text:
- Support for subpixel positioning
- Generic interface for accessing font data
- Basic UTF-8 support
Since the change decouples the font format from the 'Text_painter' and
changes the API to use the sub-pixel accurate 'Text_painter::Position'
type, all users of the utility require an adaptation.
Fixes#2716
This patch revises the implementation of nitpicker in the following
respects:
- Split the implementation into smaller files,
- Consistently use the 'Nitpicker' namespace,
- Avoid the use of format strings,
- Retire old (and hackish) debug mode,
- Removal of unused timer connection,
- Merging 'Session' into 'Session_component',
- Merging 'Mode' into 'User_state',
- Adding the notions of 'View_owner' and 'Focus' as interfaces,
- Untangle 'User_state' and 'View_stack'
