test-lib.sh: add --long-tests option

Add a --long-tests option to test-lib.sh, which enables tests to
selectively run more exhaustive (longer running, potentially
brute-force) tests.  Such exhaustive tests would only be useful if one
works on the specific module that is being tested -- for a general "cd
t/; make" to check whether everything is OK, such exhaustive tests
shouldn't be run by default since the longer it takes to run the
tests, the less often they are actually run.
Signed-off-by: NLea Wiemann <LeWiemann@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

t/README

@@ -54,6 +54,10 @@ You can pass --verbose (or -v), --debug (or -d), and --immediate
 	This causes the test to immediately exit upon the first
 	failed test.
 
+--long-tests::
+	This causes additional long-running tests to be run (where
+	available), for more exhaustive testing.
+
 
 Naming Tests
 ------------

t/test-lib.sh

@@ -80,6 +80,8 @@ do
 		debug=t; shift ;;
 	-i|--i|--im|--imm|--imme|--immed|--immedi|--immedia|--immediat|--immediate)
 		immediate=t; shift ;;
+	-l|--l|--lo|--lon|--long|--long-|--long-t|--long-te|--long-tes|--long-test|--long-tests)
+		export GIT_TEST_LONG=t; shift ;;
 	-h|--h|--he|--hel|--help)
 		help=t; shift ;;
 	-v|--v|--ve|--ver|--verb|--verbo|--verbos|--verbose)