unifdef NETSCAPE_HANG_BUG from the DTLS code. The code is not currently
enabled and I would hope that no one is using client certificates with DTLS
and Netscape, assuming it even supported it...

ok bcook@ miod@
unifdef OPENSSL_NO_NEXTPROTONEG, which is one of the last standing #ifndef
mazes in libssl. NPN is being replaced by ALPN, however it is still going
to be around for a while yet.

ok miod@
Remove trailing whitespace.