Add -Wextra (with -Wno-unused-parameter) to unix builds in addition to
-Wall -Werror.
This can successfully build everything in Sai without warnings / errors.
RFC6724 defines an ipv6-centric DNS result sorting algorithm, that
takes route and source address route information for the results
given by the DNS resolution, and sorts them in order of preferability,
which defines the order they should be tried in.
If LWS_WITH_NETLINK, then lws takes care about collecting and monitoring
the interface, route and source address information, and uses it to
perform the RFC6724 sorting to re-sort the DNS before trying to make
the connections.
PARENT_SCOPE needs adjusting in a few places for wolfssl to work, and
we need a second level export of USE_WOLFSSL through lib/CMakeLists.txt
Add noi/f32 Sai build for WOLFSSL + MINIMAL_EXAMPLES
Fix pthreads detection in the minimal examples and add it where needed.
Fix unistd.h include to be conditional on not WIN32
With this, -DLWS_WITH_MINIMAL_EXAMPLES=1 is happy and warning-free
on windows.
