Add common user-agent and server profiles to interactive tester

[timw]

After grokking the TLS support of the server/client platform and configuring a cipher-suite selection policy, it would be useful to be able to inspect the intersection of the resulting cipher-suites with common clients/servers.

e.g. web browser types/versions, openssl versions, Java versions (Oracle, HP, IBM).

This is probably useful only in the interactive tester, so might not include modification to the expression syntax and probably shouldn't leak new aliases into the general expressions, although an intersection operator might be generally useful.