check-interactive and check-noninteractive for both testsuites.

check-interactive and check-noninteractive for both testsuites.

* Makefile.am (COMMON_TESTS, TESTS): Split into ...
(NONINTERACTIVE_TESTS, INTERACTIVE_TESTS): ... these new
variables.
(check-interactive-new): Rename from check-interactive.
(check-noninteractive-new): Rename from check-noninteractive.
(check-interactive-old, check-noninteractive-old): New targets.
(check-interactive, check-noninteractive): Depend on the
respective targets for the old and the new test suites.
* doc/libtool.texi (Test descriptions): Simplify description
about check-interactive and check-noninteractive.  Add index
entries.
* NEWS: Update.

Signed-off-by: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>