Previously the navigation context (tool displaying information about
code) was using fix white color theme. This was nice for people using
light themes but for dark themes it looked like a lighhouse in the night.
The solution proposed is to use colors from the common theme for
background but also for text and code displayed in the tool panel.
These colors are supposed to be contrasted enought and readable.
Modifications are limited to AbstractNavigationContext and sub classes.
AbstractNavigationContext hold a ColorizerTheme containing colors
named as before (m_typeHighlight, m_positionHighlight, ...), this theme
is retrieved from AbstractNavigationContext::theme() and every usage
of xxxHiglight(string) is replaced by theme().m_xxxHiglight(string).
Theme initialisation is proceeded into AbstractNavigationContext constructor
with a KColorScheme.
Note: This is my second patch in this projet, please let me know if I miss anything.