added via for route calculation
changed README
added readability of EXTENSIONS.md
added readability of EXTENSIONS.md
extended informations being provided of callback
	this might be a problem for older implementations, since the info.maneuvreurs is now gone.
	maneuvreurs is now in each calculated leg of the route
use instead, which is certainly more portable, reliable, and faster.
make dist
Merge pull request #24 from axeff/via

added Via functionality