sftp daemon generates file handles correct

Also always run ssh_sftp_SUITE against own daemon as well as openssh
if existing. Corrected links test case and found that openssh has a
known bug that swaps the create link arguments. Created separate
ticket (OTP-9951) to deal with this.
Fix problem with handling error_logger events

OTP-9941
OTP-9955
Make line numbers show in logs for timetraps and abortions

OTP-9930
erts: Fix gdb command etp-ets-tabledump
Merge branch 'sverk/etp-ets-tabledump' into maint

* sverk/etp-ets-tabledump:
  erts: Fix gdb command etp-ets-tabledump
Leave control back to gen_server during supervisor's restart loop

When an attempt to restart a child failed, supervisor would earlier
keep the execution flow and try to restart the child over and over
again until it either succeeded or the restart frequency limit was
reached. If none of these happened, supervisor would hang forever in
this loop.

This commit adds a timer of 0 ms where the control is left back to the
gen_server which implements the supervisor. This way any incoming
request to the supervisor will be handled - which could help breaking
the infinite loop - e.g. shutdown request for the supervisor or for
the problematic child.

This introduces some incompatibilities in stdlib due to new return
values from supervisor:
       * restart_child/2 can now return {error,restarting}
       * delete_child/2 can now return {error,restarting}
       * which_children/1 returns a list of {Id,Child,Type,Mods},
         where Child, in addition to the old pid() or 'undefined',
         now also can be 'restarting'.
Merge branch 'siri/stdlib/hanging-restart-loop/OTP-9549' into maint

* siri/stdlib/hanging-restart-loop/OTP-9549:
  Leave control back to gen_server during supervisor's restart loop
Merge branch 'hb/stdlib/digraph_condensation/OTP-9953' into maint

* hb/stdlib/digraph_condensation/OTP-9953:
  Remove loops from the graph created by digraph_utils:condensation/1
Ensure that comments always get printed in the overview log file

OTP-9855
Merge branch 'ia/ssh/sftpd-file-handles/OTP-9948' into maint

* ia/ssh/sftpd-file-handles/OTP-9948:
  sftp daemon generates file handles correct
Skip set_attributes test on windows due to known erts bug in
file:read_file_info/1
Merge remote branch 'origin/peppe/common_test/otp-9894' into maint

* origin/peppe/common_test/otp-9894:
  Fix problem with large fun environment being copied unnecessarily
  Implement asynchronous call to print to test case log file

OTP-9894
Merge remote branch 'origin/peppe/common_test/otp-9941-9955' into maint

* origin/peppe/common_test/otp-9941-9955:
  Fix problem with handling error_logger events

OTP-9941
OTP-9955
Merge remote branch 'origin/peppe/common_test/otp-9930' into maint

* origin/peppe/common_test/otp-9930:
  Make line numbers show in logs for timetraps and abortions

OTP-9930
Merge remote branch 'origin/peppe/common_test/otp-9855' into maint

* origin/peppe/common_test/otp-9855:
  Ensure that comments always get printed in the overview log file

OTP-9855
Correct wrong location printout for ct:fail/1/2

OTP-9933
Merge remote branch 'origin/peppe/common_test/otp-9933' into maint

* origin/peppe/common_test/otp-9933:
  Correct wrong location printout for ct:fail/1/2

OTP-9933
Update vsn for R15B01
Add missing test suite
Merge branch 'peppe/common_test/otp-9933' into maint

* peppe/common_test/otp-9933:
  Add missing test suite

OTP-9933