Merge issues in `tls.el' (EMACS_22_BASE vs. trunk)

[Katsumi Yamaoka]

> Reiner Steib wrote:

>> The "problem" is loading rx and (maybe more important) unnecessary
>> differences between branch and trunk.

In the Gnus v5-10 branch, which is being synch'd with the Emacs
EMACS_22_BASE branch, the version of tls.el that uses rx has been
merged yesterday.  And tls.el came not to be able to byte compile
with XEmacs, because rx.el is not available in XEmacs.  Could it
be rewritten not using rx.el?

(info "(gnus)Emacsen")
,----
| Gnus should work on:
|
|    * Emacs 21.1 and up.
|
|    * XEmacs 21.4 and up.
`----

Regards,