Start refactoring of excluder logic
Heavily speedup print speed of exluded parts (#266)

This is achieved by reworking the logic to look at next move:
if we know the next move will set absolute E if needed, we don't need
to do it for this line. We can thus skip this G-code.
Fix potential bug in excluder logic
Merge branch 'experimental' of github.com:kliment/Printrun into experimental