[WIP] Updating navigation pattern

[thet]

Navigation:

• Do not set the .navigation-in-path class for elenents already marked with .current.
• Allow configuration of "in path" and "current" classes via in-path-class and current-class configuration options.
• Code cleanup.

[thet]

@pilz that was quick :)

[pilz]

Because it broke because of me. That always triggers me :)