[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.
[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
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.
Merge branch 'hb/remove_unused_xml_files' into maint

* hb/remove_unused_xml_files:
  Remove unused XML files
Optimize communication with file io server

The monitor ref is used in the protocol messages to optimize the
selective receive expressions.
Use erlang:demonitor(Ref, [flush]) where applicable
Merge branch 'dg/win_icon' into pu
Merge branch 'rc/break-out-asserts' into pu
Merge branch 'pn/error-logger-sup_handler' into pu
Merge branch 'ks/hipe-cleanup-escaping' into pu
Merge branch 'nox/rm-reverse-eta-conversion/OTP-10682' into pu
Merge branch 'lh/otp-optims' into pu
Merge branch 'mar/cover-fix' into pu
Merge branch 'jaf/fix-supervisor-multi-restart' into pu
Merge branch 'nox/file-receive-optim' into pu