* egil/lcnt:
  Add test suite for lcnt in tools
  Add lcnt:rt_opt/1 bindings to erts_debug
  Add runtime option to enable/disable lcnt stats
  Add auto width on string output
  Add lcnt documentation
  Add lock profiling tool

OTP-8424  Add lock profiling tool.

          The Lock profiling tool, lcnt, can make use of the internal lock
          statistics when the runtime system is built with this feature
          enabled.

          This provides a mechanism to examine potential lock bottlenecks
          within the runtime itself.

          - Add erts_debug:lock_counters({copy_save, bool()}). This option
          enables or disables statistics saving for destroyed processes and
          ets-tables. Enabling this might consume a lot of memory.

          - Add id-numbering for lock classes which is otherwise undefined.

Runtime options for copy_save.

The Lock profiling tool, lcnt, can make use of the internal lock statistics
when the runtime system is built with this feature enabled.

This provides a mechanism to examine potential lock bottlenecks within
the runtime itself.

          bug was introduced in R13B03. (Thanks to Matthew Sackman.)