Add few presolve instructions, most of them concerns sum and scalar
precompute conditions
sum/scalar
builders
usefull
Merge branch 'develop' into feature-sumscal

Conflicts:
	choco-parser/src/main/java/parser/flatzinc/ParseAndSolve.java
merge
Merge branch 'feature-sumscal' into develop
Merge with develop
Add presolve + fix bugs in DB recording
Merge branch 'feature-ps' into develop