remove old .orogen/typekit/Opaques.hpp symlink for backward compatibility

This fixes running the new orogen on already-generated orogen packages.
gen: ORO_CREATE_COMPONENT_* is now part of RTT proper, always enable it
use the RTT dynamic taskcontext creation API in deployments

This removes the need to include the Task*.hpp file and to generate
the code to instanciate the tasks themselves, thus saving quite a bit
of compilation time