Testsuite: made command syntax more uniform.

TODO

src/testsuite/Makefile.am

src/testsuite/cmd-test-binary.c

src/testsuite/cmd-test-config.c

src/testsuite/cmd-test-mailbox.c

src/testsuite/cmd-test-result-reset.c

src/testsuite/cmd-test-result.c

src/testsuite/ext-testsuite.c

src/testsuite/testsuite-common.h

src/testsuite/tst-test-result-action.c

tests/deprecated/notify/execute.svtest

tests/execute/actions.svtest

tests/execute/errors.svtest

tests/execute/examples.svtest

tests/extensions/enotify/execute.svtest

tests/extensions/imap4flags/execute.svtest

tests/extensions/include/execute.svtest

tests/extensions/mailbox/execute.svtest

tests/extensions/reject/execute.svtest

tests/extensions/spamvirustest/spamtest.svtest