Necessary to avoid travis time out trigger.

There is still an issue on ConstraintXd.
This commit *does not* compile is here for book-keeping.

[Major] Correction of bugs in JointRevoluteUnaligned and its unittest. The urdf parser nows takes into account this joint. Added a new enum in cartesian axis

[Debug] Correct bug in Symmectric test that was preventing tests to compile (at least on ubutun 14.04 LTS)

Revised the unitests, added some doc and created a "check" compilation rule. All unitests passed ok.

Adapted both the urdf parser and the romeo model to enable romeo inside pinocchio. CAUTION: Romeo is not standard any more and should be corrected, by enabling fixed joint in the urdf parser.

Added local jacobian in jacobian.hpp. Toal timings for simple-human: 1.9us for computation, 0.01 for copy,  0.3us for transform.