!!! WIP
This implements the "genec" layer wrapping mbedtls + openssl
ECDH support.
API tests are added for the parts that are implemented so far.
Stuff related to ec at all, like keys, are prefixed lws_genec_.
Stuff specific to ECDH are prefixed lws_genecdh_.
Until now the JOSE pieces only had enough support for ACME.
This patch improves the JWK parsing to prepare for more
complete support and for adding JWE, genaes and genec in
later patches.
This has no effect on user code or backward compatibility.
It moves the in-tree public api header libwebsockets.h from ./lib
to ./include, and introduces a dir ./include/libwebsockets/
The single public api header is split out into 31 sub-headers
in ./include/libwebsockets. ./include/libwebsockets.h contains
some core types and platform adaptation code, but the rest of it
is now 31 #include <libwebsockets/...>
At install time, /usr/[local/]include/libwebsockets.h is installed
as before, along now with the 31 sub-headers in ...include/libwebsockets/
There's no net effect on user code.
But the api header is now much easier to maintain and study, with 31
topic-based sub headers.
