ELNS: random, explanation:

- fix explanation of PropGreaterOrEqualXY_C
 - include geometrical function to restrict fgmt in RLNS and ELNS
 - fix 2 bugs in ELNS related to cut and domain
Change the way explained neighborhood is computed + fix a bug in SeqNeigh + LNS reacts on cut failure
Update Explained Neighborhood
LNS:

- A an abstract neighbor class,
- move fast restart to neighbor instead of LNS,
- add 2 explanation-based neighbor: cut and domain,
- add a LNS factory,
- change the way random neighborhood is computed
merge with develop
Merge branch 'feature-lns' into develop