Q module: Add join-on-invite option.

Use case: On QuakeNet you can /msg Q CHANLEV #chan <yourself> +j to
be invited once you authenticate. Anyone known on the channel (mode +k)
is able to set/unset chanlev +j for themselves.

Signed-off-by: Anders Bergh <anders1@gmail.com>
Merge pull request #524 from anders/q-invite

Q module: Add join-on-invite option.
Merge pull request #525 from anders/q-nocloakdefault

Q module: Don't enable the UseCloakedHost option by default.
Argh, fuck it. Rename fixed (pointer) versions of OnMode to OnMode2
Revert "Q module: Don't enable the UseCloakedHost option by default."

This reverts commit a7e8775efe507a980261af915ab0a3fac2e73a91.

Existing setting for existing users (who didn't do SetNV) should not change
Thanks to fred for reporting it

Reopen #525