Don't assume the BinkP VER message contains 3-space-delimited fields.

According to both FTS-1026 and FSP-1024, the "mailer version" portion of this
msg may contain spaces. Some mailers (e.g. Internet Rex), provide their version
information with spaces, e.g. "Internet Rex 2.67 beta 1a OS/2 (binkp/1.1)",
which also include a non-conformant protocol version indicator:
 " (binkp/1.1)" instead of " binkp/1.1".
Additionally, only require that "binkp/" exist in the string, to find and
parse the protocol version number, which is apparently critical to the proper
operation of the protocol. This should resolve issue #185 reported by altere.

I'm also storing the entire VER response in the binkp.remote_ver property and
this will break the older Mystic/BinkP work-arounds in binkit.js. I dont' think
we really need those workarounds any longer however. We'll soon see I guess.