* josevalim/supervisor-get-callback-module/PR-1000/OTP-13619:
  Return callback module in supervisor format_status

The previous implementation of supervisor:get_callback_module/1
used sys:get_status/1 to get the supervisor inner state and
retrieve the callback module. Such implementation forbids any
other supervisor implementation that has an internal state
different than the #state{} record in supervisor.erl.

This patch allows supervisors to return the callback module
as part of the sys:get_status/1 data, no longer coupling the
callback module implementation with the inner #state{} record.

Notice we have kept the clause matching the previous
sys:get_status/1 reply for backwards compatibility purposes.

* siri/observer/improve-trace/OTP-13481:
  [observer] Update user guide
  [observer] Automatically add active node
  [observer] Allow more trace flags on procs/ports from GUI
  [runtime_tools] Don't trace the trace client port
  [runtime_tools] Allow setting trace flag 'exiting' with dbg
  [observer] Add more default match specs for messages
  [observer] Add test of new Ports tab
  [observer] Improve appearance in Trace tab
  [observer] Allow multiple select in Ports tab
  [observer] Make right click menu act on the "expected pid"
  [observer] In Trace tab, show procs/ports for selected node only
  [observer] Add right click menu in Table tab
  [observer] Add menu option to set default MS for send/receive
  [observer] Add tracing of ports
  [ttb] Allow setting trace flags on ports
  [observer] Set correct parent in Label dialog
  [observer] Add Ports tab in GUI
  [observer] Add functionality in GUI for trace pattern on messages
  [ttb] Set trace patterns on messages

Conflicts:
	lib/observer/src/observer_wx.erl

When setting trace flags on 'new_processes' or 'new_ports', the
currently active node is now automatically added if no other node is
traced.

* Only allow single selection of modules
* Add right click menu to remove module
* Allow multiple selection of nodes, and show procs/ports for ALL
  selected nodes
* On right click, only show menu items that make sense for the current
  content and selection
* Add tooltips with help text

This is helpful when selecting ports to be traced.

If multiple processes were selcted, "Process Info" and "Kill Process"
menu choices would pick the first pid in the selection list, i.e. the
last selected process. This is now changed so the process under the
mouse pointer is used instead.