Generalize routing engine

Most routing WEB services works the same way.
This class allow to add a routing engine, by simply setting some
properties.

Signed-off-by: Guilhem Bonnefille <guilhem.bonnefille@gmail.com>
Routing: suppress OSRM specific code

All OSRM feature can be implemented with generic routing engine.

Signed-off-by: Guilhem Bonnefille <guilhem.bonnefille@gmail.com>
Routing: suppress Google

Suppress Google specific code as all can be done via generic
web engine.

Signed-off-by: Guilhem Bonnefille <guilhem.bonnefille@gmail.com>
Routing: refactor

All related Web stuff should be hosted by VikRoutingWebEngine.
Ideally, VikRoutingEngine should stay independent from any
technical implementation.

For exemple, we can imagine a future set of routing engine
running offline.

Signed-off-by: Guilhem Bonnefille <guilhem.bonnefille@gmail.com>
Fix selection of trackpoint via Edit Trackpoint button.

Need to set current bounding box for the trackpoint search.
Error was introduced by commit SHA1:79773236f27a9ab34622b2739f929737144b67b2
Don't silently fail on attempting to split to a track.

Annoyingly my new GPS output had a dodgy timed trackpoint,
 so I was wondering why the split functionality wasn't working.

This now gives a chance to go to the offending point,
 so that hopefully if it's only one, one can delete it to fix the issue.