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.
inets: httpc improve pipelining
httpc: Enhanched error handling
inets: httpc make httpc_cancel_request/[1,2] asynchronous
inets: httpc - Remove dead error handling code

Some error handling is only relevant for functions that
end up in gen_server:call and not in gen_server:cast.
Add some more comments about what the test does

This changed the lines so the results now differ.
Fix a comment
Adopt a convention about unknown modules
Use the modern version of is_subtype
No reason for calls to unknown modules
Adopt a convention about unknown modules
Fix crash when using remote types in the tail of list types

Hans Bolider reported a dialyzer crash when using a remote type in
the tail position of a maybe_improper_list() declaration. A test
was created (by extending an existing module of the testsuite)
and erl_types was modified to expand the remote type and not pass
it unexpanded to subsequent phases in the processing.
Use normal- instead of scaled timeouts in test case
ssl: Honor TLS client ECC extension

Also the server should only send ECC point formats extension not ECC curve
extension.
Merge branch 'kostis/dialyzer_R16B02_fixes/OTP-11374' into maint

* kostis/dialyzer_R16B02_fixes/OTP-11374:
  Fix crash when using remote types in the tail of list types
  Adopt a convention about unknown modules
  No reason for calls to unknown modules
  Use the modern version of is_subtype
  Adopt a convention about unknown modules
  Fix a comment
  Add some more comments about what the test does
Merge remote branch 'origin/peppe/common_test/missing_error_reports' into maint

* origin/peppe/common_test/missing_error_reports:
  Use normal- instead of scaled timeouts in test case
ssl: Fix dialyzer spec
Merge branch 'ia/ssl/ecc-gnutls/OTP-11370' into maint

* ia/ssl/ecc-gnutls/OTP-11370:
  ssl: Fix dialyzer spec
  ssl: Honor TLS client ECC extension
Merge branch 'ia/inets/http-client-cancel-request/OTP-11312' into maint

* ia/inets/http-client-cancel-request/OTP-11312:
  inets: httpc - Remove dead error handling code
  inets: httpc make httpc_cancel_request/[1,2] asynchronous
  httpc: Enhanched error handling
  inets: httpc improve pipelining
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.