Add module integration tests

tests/mods/modules/bcmath/bcmath.php

@@ -0,0 +1,26 @@
+<?php
+/**
+ * This page should print 'OK' if everything works,
+ * 'FAIL' or nothing if an error occured.
+ */
+ini_set('display_startup_errors', 1);
+ini_set('display_errors', 1);
+error_reporting(-1);
+
+$a = '1.234';
+$b = '5';
+
+$num1 = bcadd($a, $b);     // 6
+$num2 = bcadd($a, $b, 4);  // 6.2340
+
+if ($num1 != 6) {
+	echo 'FAIL: ' . $num1;
+	exit(1);
+}
+
+if ($num2 != 6.2340) {
+	echo 'FAIL: ' . $num2;
+	exit(1);
+}
+
+echo 'OK';