remove eztrace modules from root - eztrace will intercept our interface coreblas (cudablas, later) functions

change the name of the option CHAMELEON_USE_FXT in CHAMELEON_ENABLE_TRACING, there will be other way than fxt to trace the application

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 .