* Makefile.am (TESTS_ENVIRONMENT): New variable.
(check-all): New phony target to run all tests.
* tests/gpgme/gpgme-defs.scm (have-gpgme?): New function that tests
whether the GPGME test suite is available instead of exiting the
process.
* tests/gpgscm/init.scm (export): New macro.
* tests/gpgscm/tests.scm (run-tests): New function.
(load-tests): Likewise.
* tests/gpgme/run-tests.scm: Simplify and move the parsing of the list
of tests to 'all-tests.scm'.
* tests/gpgsm/run-tests.scm: Likewise.
* tests/migrations/run-tests.scm: Likewise.
* tests/openpgp/run-tests.scm: Likewise.
* tests/gpgme/Makefile.am: To select the tests to run, use the
variable 'TESTS'.  This harmonizes the interface with the automake
test suite.
* tests/gpgsm/Makefile.am: Likewise.
* tests/migrations/Makefile.am: Likewise.
* tests/openpgp/Makefile.am: Likewise.
* tests/openpgp/README: Likewise.
* agent/all-tests.scm: New file.
* common/all-tests.scm: Likewise.
* g10/all-tests.scm: Likewise.
* g13/all-tests.scm: Likewise.
* tests/gpgme/all-tests.scm: Likewise.
* tests/gpgsm/all-tests.scm: Likewise.
* tests/migrations/all-tests.scm: Likewise.
* tests/openpgp/all-tests.scm: Likewise.
* tests/run-tests.scm: Likewise.