* Allow CMAKE to generate ws and wss transports
I guess there is little use of just ws transport, so by default
GnuTLS (and libsodium) are enabled

* cmake libzmq including wss transport (ubuntu 19.10 and ubuntu 19.10 + wsl 1.0)
test_security_fails (libsodium assert !?)

* updated relicense

* make external libs gnutls nss sodium optional

* #ifdef WSS classes and functions, build test*ws* only if correct libs are included, warning if libs not present

* make libsodium optional

* cmake fix tests TIPC transport

* clang-format pointed out a wrongly placed #ifdef

* GnuTLS before 3.6.7 is not safe

* msvc doesn't agree with strlen in array declaration, test_socks now at least compiles on windows

* windows: libsodium build fails, missing include dirs set by env var

* ws transport test only works when GnuTLS is found

* Fixed condition to use NSS / built in SHA1, so that test_ws_transport should now pass, also when GnuTLS is not found