Add the possibility to enter Chameleon with an existing starpu (Need to be cleanup on the starpu_initialized function)

test external definitions to avoid duplicates: remove cmake_modules directory and set cmake_modules as an external project via svn propedit svn:externals .

add MORSE_Pause/Resume function to avoid CPU consumption when no tasks have to be executed - call starpu_pause/resume, do nothing for quark (no need)