Fix erlang:is_process_alive/1
erts: Fix copy error in erlang:delete_element/2

Off-by-one error in element copy.
erts: Refactor erlang:insert_element/3 for clarity
[observer] Add debug printouts in ttb_SUITE

To troubleshoot failed test case trace_resumed_after_node_restart on
windows.
[common_test] Add -force_stop skip_rest option when repeating tests

To allow a repeated test to finish immediatly, 'skip_rest' option can
now be used in combination with 'force_stop'. If this option is used,
only the current testcase will be completed after timeout is reached
when repeating with 'duration' or 'until'.
[common_test] Add support for testing repeated testruns

ct_test_support which is used in common_test's own tests did not
support testruns with -repeat, -duration or -until options. This is
now added.
[reltool] Clean up work dir after test

This is to save space in daily tests.
Result of failed test cases are still saved.
[test_server] Don't hang due to invalid io request

A bug in test_server_gl caused io requests containing invalid data
(i.e. not unicode:chardata()) to hang, since no io reply was
sent. This has been corrected.
[common_test] Add tests for repeated testruns

ct_repeate_testrun_SUITE is added, which tests the following options
to ct_run:

-repeat N
-duration [-force_stop [skip_rest]]
-until [-force_stop [skip_rest]]
[common_test] Document '-force_stop skip_rest' option to ct_run
Be less eager requesting wakeup for cleanup jobs
Fix `+sws' and `+swt' system flags
Merge branch 'siri/common_test/force_stop-skip_rest/OTP-10856' into maint

* siri/common_test/force_stop-skip_rest/OTP-10856:
  [common_test] Document '-force_stop skip_rest' option to ct_run
  [common_test] Add tests for repeated testruns
  [common_test] Add support for testing repeated testruns
  [common_test] Add -force_stop skip_rest option when repeating tests
Merge branch 'siri/test_server/hanging-io-request/OTP-10991' into maint

* siri/test_server/hanging-io-request/OTP-10991:
  [test_server] Don't hang due to invalid io request
Remove unused XML files

incompatible.xml and highlights.xml haven't been included anywhere
for a long time.
Make port close not be delayed

Drivers are dereferenced when the port is completely gone, in the operation
scheduled with erts_schedule_thr_prgr_later_op. If we use
erts_schedule_thr_prgr_later_cleanup_op, it may not happen
for a long time and the driver can not be unloaded.

We can not dereference the driver before the thread_progress_later
thing, because references to the driver may exist in other threads, so
the unloading of the driver may free locks held by other schedulers and
whatnot.
Merge branch 'rickard/is_process_alive/OTP-10926' into maint-r16

* rickard/is_process_alive/OTP-10926:
  Fix erlang:is_process_alive/1
Merge branch 'rickard/thr_prgr_later_op/OTP-10994' into maint-r16

* rickard/thr_prgr_later_op/OTP-10994:
  Make port close not be delayed
  Be less eager requesting wakeup for cleanup jobs
Merge branch 'rickard/sys-flags/OTP-11000' into maint-r16

* rickard/sys-flags/OTP-11000:
  Fix `+sws' and `+swt' system flags
Merge branch 'egil/r16/fix-delete_element/OTP-10932' into maint-r16

* egil/r16/fix-delete_element/OTP-10932:
  erts: Refactor erlang:insert_element/3 for clarity
  erts: Fix copy error in erlang:delete_element/2