Some servers have very restrictive TLS stacks that respond badly to a bug in the SChannel TLS implementation, meaning that TLS has to be limited to 1.0. Add ClientOptions.tlsOptions. This is a method of passing options into the TLS stack. It's currently only used for the TLS 1.0 workaround in SChannel, but we might reasonably expose other options in the future, such as limiting cypher suites. Disables use of SSLv3 for SChannel Also updates the coding style in SchannelContext a bit. Test-Information: Compiles on both OS X and Windows(SChannel). OS X doesn't show the new option. Windows shows it, and remembers it between logins. Not tested against a server requiring 1.0 only, but a previous hack with the same approach was tested. Change-Id: I1e7854d43811fd173f21f98d4dc3915fc7a4b322