Updating changelog.
Instruction for generating jar file
Performance improvements in AbsXeqY and ElementVariable.
Improving performance by changing queueIndex for the constraints and simple tuning.
New element generation in Scala wrapper.

New way of specifying element constraint using normal array access in
Scala. Based on the method proposed in project
https://github.com/Sciss/Poirot/
Use of Scala 2.10.3
Code clenaing.
Adding commands to generate API documentation.
Fixing warnings in API documentation.
Removing not stable features stochastic and sat
Updating CHANGELOG to reflect refactoring of stochastic and JaSAT feature
Changing version to 4.0.0
Merge branch 'release/jacop-4.0.0'
Merge remote-tracking branch 'upstream/master' into sbtfied
v3.4.0 corresponding to upstream v4.0.0