* bd/doc-fixes:
  Fix minor documentation errors

* jn/supervisor_child_count_only:
  Add count_children/1 to supervisor.erl to determine the number of

OTP-8436  Added supervisor:count_children/1 to count the number of children
          being managed without the memory impact of which_children/1.
          (Thanks to Jay Nelson.)

children being managed without the memory impact of which_children/1

The function which_children/1 returns a list of the child processes
currently being supervised, but it has the penalty of creating a new
list thereby consuming more memory.  In low memory situations it is
often desirable to know which supervisor may have generated many
processes, but the act of discovering the culprit should not cause the
node to crash (or worse a different node if the kernel kills one
randomly).  The new function count_children/1 can give an indication
of which supervisor is taxing resources the most without adding to the
burden.  Rather than creating a new list, it walks the supervisor's
internal children structure using an accumulator function so that any
used memory can be incrementally collected yet the resulting count can
still be obtained.

The return result of count_children/1 is a property list of counts
containing:
  - {specs, Total_Num_Child_Specs}
  - {active, Num_Active_Child_Processes_Of_Supervisor_Or_Worker_Type}
  - {supervisors, Num_Supervisor_Type_Children_Including_Dead_Processes}
  - {workers, Num_Worker_Type_Children_Including_Dead_Processes}

This patch was made in response to mailing list discussions of the
problem diagnosing heavily taxed production systems.  I cannot find
the original request, but http://www.erlang.org/cgi-bin/ezmlm-cgi/4/35060
is my original post of the patch.

          prompt strings (io:get_line/{1,2}). io_lib is also updated to
          format prompts with the 't' modifier (i.e. ~ts instead of ~s).

Fix three minor typos and reorder one of a pair of lists of functions so that
the ordering is consistent.

          configuration parameter shell_prompt_func can be used for
          customizing the Erlang shell prompt.

          environment after a number of bugs are fixed and some features
          are added in the documentation build process.

          - The arity calculation is updated.

          - The module prefix used in the function names for bif's are
            removed in the generated links so the links will look like

            http://www.erlang.org/doc/man/erlang.html#append_element-2

            instead of

            http://www.erlang.org/doc/man/erlang.html#erlang:append_element-2

          - Enhanced the menu positioning in the html documentation when a
            new page is loaded.
          - A number of corrections in the generation of man pages (thanks
            to Sergei Golovan)
          - Moved some man pages to more apropriate sections, pages in
            section 4 moved to 5 and pages in 6 moved to 7.
          - The legal notice is taken from the xml book file so OTP's
            build process can be used for non OTP applications.

* sv/sys_get_status:
  Teach sys:get_status/1,2 to call Mod:format_status/2
  gen_fsm: Fix format_status/2 to handle Pids

OTP-8324  The ability for the gen_server and gen_fsm callback modules to
          format their own state for display under the sys:get_status/1,2
          calls has been restored and documented. (Thanks to Steve
          Vinoski.)