The test_server application has previously been deprecated.

In OTP 19, we will move relevant parts of test_server into the
common_test application. Test suites that include test_server.hrl
must be updated to include ct.hrl instead. Test suites that include
test_server_line.hrl must removed that inclusion. Test suites that
call the test_server module directly will continue to work in OTP 19.

The test suites for Erlang/OTP are built and executed in exactly
the same way as previously.

Here are some more details.

The modules test_server*.erl and erl2html2.erl in lib/test_server/src
have been moved to common_test/src.

The test_server.hrl and test_server_line.hrl include files have
been deleted. The macros in test_server.hrl have been copied into
lib/common_test/include/ct.hrl.

The ts*.erl modules and their associated data files in
lib/test_server/src has been been moved to the new directory
lib/common_test/test_server. The ts* modules are no longer built
to lib/common_test/ebin. They will only built when 'make release_tests'
is executed.

The test suite for test_server has been moved to lib/common_test/test.

The rest of the files have been deleted.

Remove the old kludgy parse transformations and line numbers
macros in common_test and test_server, and use the line numbers
in exceptions instead.

* fh/common_test-includes:
  make it possible to include ct.hrl using include_lib
  Include test_servers's include files in the bootstrap

OTP-8379  It is now possible to include the ct.hrl using the -include_lib
          directive. (Thanks to Fred Hebert.)

It is major annoyance that ct.hrl cannot be included
using "-include_lib". The problem is that ct.hrl in turn
includes the test_server include files using "-include".
Fix it by using "-include_lib" in ct.hrl.