add comments for the supported command line options

removed two extra opcode number at start end end
generates get_<arch>_irn_opcode()
generates #ifdefs's around header file
calls <arch>_register_additional_opcodes only if $additional_opcodes is set

more comments added

fixed copy inserter bug
changed debugging stuff

omit copy if in==out

fixed the assert and put the whole assert code into #ifdef NDEBUG

Fixed construction of spill-slots and frame type. Aligment was not taken into account (alignment might be bigger than size!)

be_get_empty() checks now that the set is really empty :-)
some comments added

FIRM_DBG_REGISTER() with decl must been the last decl
removed asserts that the empty set is empty. This is now checked in be_get_empty()

be_node_classify() should classify be_Return as a branch. This might be useless
as be_Return consume all register and should be last anyway, but it happen that
keep'ed nodes otherwise are scheduled after Return ...

be_get_IncSP_pred() added

more docu added