Enable host-user matching for bot links
Fix passing no user into user_has_host() not properly looking up user
Only validate hosts for the linking bot, not all

This fixes the previous code causing the first user to have the matching
host to be returned, thus causing a non-match on the user handle and
then denying the link. This change now allows multiple users/bots
to have the same hostname, but requires that the linking bot
matches its own hosts
Fix leaf bots being able to initiate userfile transfer to hubs
Only accept share lines from the bot sending the userfile
Fix non-hubs being able to update other bots
Validate sooner when the update is first offered and initiated
This check doesn't work here as a separate dcc is created for transfer
Add aggressive check before transfering userfile for compat
No longer need to share version to update.mod since 428466cf
bot_shareupdate() should be private now
Detect invalid version lines
Ensure proper ordering in linking negotiation
Merge branch 'link-state' into maint

* link-state:
  Ensure proper ordering in linking negotiation
Merge branch 'protect-telnet-user-match' into maint

* protect-telnet-user-match:
  Only validate hosts for the linking bot, not all
  Fix passing no user into user_has_host() not properly looking up user
  Enable host-user matching for bot links

Conflicts:
	doc/UPDATES
Merge branch 'streaming-userfile-aggressiveness' into maint

* streaming-userfile-aggressiveness:
  Add aggressive check before transfering userfile for compat
  This check doesn't work here as a separate dcc is created for transfer
  Validate sooner when the update is first offered and initiated
  Fix non-hubs being able to update other bots
  Only accept share lines from the bot sending the userfile
  Fix leaf bots being able to initiate userfile transfer to hubs

Conflicts:
	doc/UPDATES
Merge branch 'fix-invalid-v' into maint

* fix-invalid-v:
  Detect invalid version lines
Merge branch 'remove-update-v' into maint

* remove-update-v:
  bot_shareupdate() should be private now
  No longer need to share version to update.mod since 428466cf