Conflicts:
	lib/common_test/test/Makefile

The ct_release_test module provides support for testing
upgrade/code_change of one or more applications within the Erlang/OTP
product. This commit adds tests to the common_test/test directory.

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.

Since no test suites includede test_server.hrl, there is no need
to have test_server in the include path or code path.

OTP-10126