This then makes sure that all things libcoap are properly initialized
before use, and coders realize they need to do this.
Note: coap_new_context() continues to make sure that coap_startup()
is invoked if not done previously, but this may be too late.
This means that apps need to have no knowledge of what IP support is available.
Updates coap_uri_into_options() and coap_resolve_address_info()
which have only been recently added to develop branch and are not in any
previous release.