*) Delete CPU and CIA arguments from hw_io_*_buffer transfers.

*) Delete CPU and CIA arguments from hw_io_*_buffer transfers.
   Instead save them in the sim_hw structure.
*) Route sim-core accesses to hw devices through the sim_hw module.
*) Route hw device requests to abort/halt through the sim_hw module.
*) Add print parameter to hw_tree_print() function.
*) Add sim_engine_vabort () function.