Merge pull request #8 from tonipenya/master

Implemented SingleWeightFactor.
Fix Carindality faction when it receives inifinity messages
Merge pull request #9 from tonipenya/master

[bug-fix] getMessage didn't comply with the getMessage contract for Weighting and SingleWeight factor.
Merge pull request #10 from tonipenya/master

[bug-fix] nElementsA was being decremented when calling to removeNeighbor for a non-neighbor in AbstractTwoSidedFactor.
Merge remote-tracking branch 'upstream/master'
Fix a bug where proxied factors where not correctly initialized
Merge pull request #11 from RMASBench/master

Fix unproperly initialized proxied factors
Fix the WeightingFactor factor
Merge pull request #12 from RMASBench/master

Fix the WeightingFactor factor
Fix the SingleWeightFactor factor.