Added pal-gazebo-worlds

Add recording argument
Add box and world for pg_demo
Use a single table in stamping demo
Update depend.mk

Add recording and extra_gazebo_args parameters

Update republish + config for position control

Add entity RosQueuedSubscribe

Add Event::setOnlyUp
Add entity VariadicOp and update Mix_of_vector entity.
Make Switch derive from VariadicAbstract
Enhance VectorSelecter and MatrixComparison
Add command Sot::getSize
Fix usage of activated DoF in entity Sot
Fix some compilation warning
Make Multiply_of_* a VariadicOp instead of BinaryOp

Add Event::setOnlyUp
Add entity VariadicOp and update Mix_of_vector entity.
Make Switch derive from VariadicAbstract
Enhance VectorSelecter and MatrixComparison
Add command Sot::getSize
Fix usage of activated DoF in entity Sot
Make Multiply_of_* a VariadicOp instead of BinaryOp
Clean code of operator PoseUThetaToMatrixHomo, MatrixHomoToPoseUTheta…

Improves IntegratorEuler, makes a vector version and
adds an abstract integrator.

Not sure it is gonna work...

The naming scheme breaks the usual convention of robotpkg.

[wip/pal-transmissions] Add chaining of the environment to make openrobots having the highest priority.