Update libcoap functions that need to be called locked with a name
suffix of _locked.
Move matching functions out of coap_threadsafe.c to be coded just ahead
of the newly renamed _locked function.
Properly define the _locked function in the appropriate _internal.h file
for documentation, removing the #defines from coap_threadsafe_internal.h.
Work in progress for all the functions.
Remove coap_lock_* requirements for testdriver (coap_delete_node()).
Jon Shallow
622050a957