Remove ^L characters hidden randomly in the code. Not those used in text files as delimiters.

While working on a tool that processes Erlang code and testing it against this repo,
I found out about those little sneaky 0xff. I thought it may be of help to other
people build such tools to remove non-conforming-to-standard characters.
Merge branch 'fenollp/treewide_remove_unexpected_0xff/OTP-11323' into maint

* fenollp/treewide_remove_unexpected_0xff/OTP-11323:
  Remove ^L characters hidden randomly in the code. Not those used in text files as delimiters.
Change skip vs auto_skip behaviour

When a configuration function returns {skip,Reason}, all affected test
cases will now get status skipped, not auto_skipped.
Furthermore, auto skipped cases will be reported as "auto_skipped" in
the textual log file (not "skipped", as in previous versions).

OTP-11305
Fix problem with handling Config and FW reports correctly
Change status from skip to auto_skip for config func that fails due to require
Correct various bugs related to auto_skip and groups
Correct tests cases that fail because of modified events
Change report tag for failed init_per_testcase from skipped to auto_skipped
Fix problem with suites and groups skipped from test specification
Add test cases for new and modified functionality
Fix problems with info functions and add more tests
Modify the auto_skip report for group config funcs to include group name

Also correct failing test cases and find and fix remaining bugs.
Merge remote branch 'origin/peppe/common_test/change_skip_behaviour' into maint

* origin/peppe/common_test/change_skip_behaviour:
  Modify the auto_skip report for group config funcs to include group name
  Fix problems with info functions and add more tests
  Add test cases for new and modified functionality
  Fix problem with suites and groups skipped from test specification
  Change report tag for failed init_per_testcase from skipped to auto_skipped
  Add tests for skipping parallel groups
  Correct tests cases that fail because of modified events
  Correct various bugs related to auto_skip and groups
  Change status from skip to auto_skip for config func that fails due to require
  Fix problem with handling Config and FW reports correctly
  Change skip vs auto_skip behaviour

OTP-11305
Prepare release