Use automake's support for parallel tests

In current automake, there's no way to have the list of tests be
dynamic, so generate that when running configure as well as a local
hook to update the list if it's changed.

Also enable colourised test output.

bin/varnishtest/Makefile.am

 #
 
-TESTS_PARALLELISM = 3
-check: varnishtest
-	./varnishtest -i -j$(TESTS_PARALLELISM) $(srcdir)/tests/*.vtc
-	@echo "==================="
-	@echo "All tests succeeded"
-	@echo "==================="
+VTC_LOG_COMPILER = ./varnishtest -v -i
+TEST_EXTENSIONS = .vtc
+TESTS = @VTC_TESTS@
+
+# Make sure we run check-local first
+check: check-local check-am
+# See if list of checks have changed, recheck
+check-local:
+	if [ "$$(cd $(srcdir) && echo tests/*.vtc)" != "@VTC_TESTS@" ]; then \
+		cd $(top_builddir) && ./config.status --recheck ; \
+	fi
 
 DISTCLEANFILES = _.ok
 

configure.ac

@@ -12,7 +12,7 @@ OCFLAGS="$CFLAGS"
 AC_CANONICAL_SYSTEM
 AC_LANG(C)
 
-AM_INIT_AUTOMAKE([foreign])
+AM_INIT_AUTOMAKE([foreign color-tests parallel-tests])
 AC_DISABLE_STATIC
 AC_PROG_LIBTOOL
 
@@ -526,6 +526,10 @@ fi
 
 AC_DEFINE_UNQUOTED([VCC_CC],"$VCC_CC",[C compiler command line for VCL code])
 
+# Stupid automake needs this
+VTC_TESTS="$(cd $srcdir/bin/varnishtest && echo tests/*.vtc)"
+AC_SUBST(VTC_TESTS)
+
 # Generate output
 AC_CONFIG_FILES([
     Makefile