Several new ops are planned for tls... so better to bite the bullet and
clean it out to the same level as roles + event-libs first.
Also adds a new travis target "mbedtls" and all the tests except
autobahn against mbedtls build.
Everything in lws outside esp32 was changed to use lws_snprintf() a while ago.
This fixes a couple of stragglers and removes the preprocessor mangling.
After startup, and once per day, check the validity dates on our ssl certs,
and broadcast callbacks with the information so interested plugins can
know.
If our clock is < May 2016, we don't try to judge the certs, because clearly
we don't know what time it is.
- introduce lib/tls/mbedtls lib/tls/openssl
- move wrapper into lib/tls/mbedtls/wrapper
- introduce private helpers to hide backend
This patch doesn't replace or remove the wrapper, it moves it
to lib/tls/mbedtls/wrapper.
But it should be now that the ONLY functions directly consuming
wrapper apis are isolated in
- lib/tls/mbedtls/client.c (180 lines)
- lib/tls/mbedtls/server.c (317 lines)
- lib/tls/mbedtls/ssl.c (325 lines)
In particular there are no uses of openssl or mbedtls-related
constants outside of ./lib/tls any more.
