Remove warnings.

Please remove useless arguments in functions and methods.
jac_point_chain: assert that Robot::NBDOF>=6
add has_parent helper
use has_parent in crba
remove HAS_PARENT from models
remove tools/algos #includes from models

and the forward declarations too. It fix the performance regression
that came with the visitors implementation. The loss of performance
apparently did not came from the visitors themselves but from the fact
that I added the new algorithms headers and forward declarations
to the simple_humanoid and simple_arm.

It also explains why the generated models were not affected.

Before this commit

    $ nm build-release_brm/tests/libsimple_humanoid.so | wc -l
    962
    *************
    Model NBDOF : 35
        average execution time :
    jcalc: 2.15047µs
    bcalc: 2.84113µs
    rnea: 7.12577µs
    rnea (without jcalc): 4.60182µs
    crba: 7.74877µs
    crba (without jcalc): 5.2321µs
    jac_point_robot (without bcalc): 12.487µs
    *************
    Model NBDOF : 31
    average execution time :
    jcalc: 2.10052µs
    bcalc: 2.78628µs
    rnea: 6.21797µs
    rnea (without jcalc): 3.93645µs
    crba: 6.22656µs
    crba (without jcalc): 3.84575µs
    jac_point_robot (without bcalc): 8.04626µs

After this commit

    $ nm build-release/tests/libsimple_humanoid.so | wc -l
    778
    *************
    Model NBDOF : 35
        average execution time :
    jcalc: 2.10535µs
    bcalc: 2.8344µs
    rnea: 6.23657µs
    rnea (without jcalc): 3.90795µs
    crba: 7.65815µs
    crba (without jcalc): 5.25423µs
    jac_point_robot (without bcalc): 12.7603µs
    *************
    Model NBDOF : 31
        average execution time :
    jcalc: 2.09651µs
    bcalc: 2.78867µs
    rnea: 6.20554µs
    rnea (without jcalc): 3.95253µs
    crba: 6.09986µs
    crba (without jcalc): 3.86598µs
    jac_point_robot (without bcalc): 8.04133µs
Switch from BOOST_STATIC_ASSERT to C++11 static_assert.

On gcc-4.4.3 (ubuntu 10.04 LTS) the boost assert fails at compile
time. In addition as the code is already needing C++11, switch to
the C++11 static_assert standard.