htons on uint16_t in flow mod/add flow remove callback

Flow remove callback doesn't fire, because the switch
tries to connect back to us to tell us about it.
Might be able to fix this with a siwtch config, or need to
implement controller listener anyway...
Remove spurious comment

Still need a good way to choose between different apps..
Maybe apps should all implement app_init(base) and then
you choose in the makefile (make telex, make switch, etc)