Ability to store/restore roster's groups roll state

Implementation is quick-and-dirty. State saved in private server
storage per jc. "roster" tag used with "emacs-jabber" xmlns. Value is
newline-separated list of groups to rollup (assumed that group name
can't contain newline).
Fix for case when we dont have saved roll state (server result is empty)
Private storage now used for bookmarks and roll state saving
Fix for case when there is no rolled up groups or when where is just one such group
Save empty rolled groups list anyway, for consistensy
Merge branch 'upstream' into store-groups

# By Magnus Henoch (18) and others
# Via Magnus Henoch
* upstream: (31 commits)
  Ensure that jabber-bookmarks is loaded in jabber-jid-bookmarkname
  Fix :get function for jabber-roster-default-group-name
  If all accounts are already connected in jabber-connect-all, say so
  Make nick coloring work in Emacs24
  Don't display "added to roster" messages for initial roster population
  Don't add extra newline when using STARTTLS
  Fix reporting of STARTTLS negotiation errors
  Fix error handling for old-style SSL/TLS connections
  Support native GnuTLS for STARTTLS
  s/screen/tmux/ in jabber-tmux.el
  Mention tmux alerts in the documentation
  Add tmux alerts
  Fix build with automake > 1.11.4
  Avoid groupchat buffer on RET in roster if we're not 100% sure it's a groupchat (bug 3483380)
  Version 0.8.91
  * jabberd.el (jabberd-handle): Update for new namespace handling.
  Use namespace prefixes declared on stream root element
  jabber-core: Fix header parsing
  Fix :get function for jabber-roster-default-group-name
  Use xml-parse-region to parse stream header
  ...

Conflicts:
	jabber-roster.el
	jabber.texi
Typo fixed. According to xep-0202 "query" from xep-0012 replaced by "time"
guard create-image with error handler
jabber-disconnect: Display "Already disconnected" if that is the case
Update docstring for how to hide offline contacts permanently
"Authentication succeeded" message to mention which account
jabber-ping.el: require jabber-menu

Needs jabber-jid-info-menu.