[option] -l=XX -hbfs performs hybrid best-first search with LDS using fixed discrepancy as probing procedure

Should try redefining Cost as a class as in tb2paretopair.hpp

This reverts commit b1b71d6b.

Changed this to > 0.

overflow bit in the cpu). This relies on built-in functions available
in gcc/g++ (versions above 5.0) and clang > 3.5. So it should run on
Linux, MacOSX and Windows (as far as these compilers are used). See eg.
http://clang.llvm.org/docs/LanguageExtensions.html#checked-arithmetic-builtins

 - declaration of bool Add/Sub/Mul(Cost,Cost,*Cost) that add,
   subtract, multiply two Costs, leaves the result in the last Cost
   pointed Cost and return True only in case of overflow.

 - using them in few crucial project/extend but probably more need to
   be replaced.

I see no performance changes using g++ (make test).

It's a good idea to test clang++ also. I tested version 4.0 that
apparently generates faster code than g++ (single test, on a CELAR
instance cpu time went from 17.2" to 16.8") and also plenty of
warnings !

[misc] modify random generator in order to be able to generate clauses (by changing tightness in rungenerate)

[error] bug correction when using clauses inside BTD (we need to take care of cost moves between clusters)

[code] new weighted clause global cost function ; weighted degree heuristic now used by default always (up to 1million vars)

Merge branch 'master' of git+ssh://scm.mulcyber.toulouse.inra.fr//var/lib/gforge/chroot/scmrepos/git/toulbar2/toulbar2

[code] for tree decomposition input file, it assumes a valid rooted forest and it will not apply any other optional transformations (like split, merge, etc) on the tree structure

[option] control if the initial solution given as an input file (with extension .sol) will be used both for upperbound and value heuristic (by default) or upperbound only (option -x: )

[option] a valid tree decomposition can be given as input file (with .cov extension or using -O=filename)

[option] a valid tree decomposition can be given as input file (with .cov extension or using -O=filename)

Merge branch 'master' of git+ssh://scm.mulcyber.toulouse.inra.fr//var/lib/gforge/chroot/scmrepos/git/toulbar2/toulbar2

Merge branch 'master' of git+ssh://scm.mulcyber.toulouse.inra.fr//var/lib/gforge/chroot/scmrepos/git/toulbar2/toulbar2
[doc] Toulbar2 Testing and benchmarking doc

[code] INCOP starts with current best solution if given as input else uses unary EAC/VAC support values

[code] code optimization (devirtualizes using C++-11 keyword final small methods and classes WCSP and Solver -potential issue for VNS?- ; new NaryConstraint class being union of a map and/or an array depending on compression gain) ; cpu-time with high precision (microseconds) ; [error] VAC value heuristic (now used by default if VAC selected) must update EAC queue more often to ensure correct EAC values ; [error] merging functional variables uses setTuple instead of addToTuple