Add the new test suite.

This test suite has been in use for a long time now, in place of the obsolete and unmanageable testparser.py and testfuncs.py. It verifies the complete optimizer output to stdout and stderr, to ensure that the output matches the expectations.

See unit_tests/README.txt for more info.

unit_tests/regression.suite/state-in-udf-2.lsl

@@ -0,0 +1,21 @@
+x()
+{
+    // FIXME: When optimizing this, a naked 'state default;' is left.
+    // That is forbidden.
+    do
+    {
+        state default;
+        do
+            state default;
+        while (0);
+        if (1)
+            state default;
+        if (1)
+            ;
+        else
+            state default;
+    }
+    while (0);
+}
+
+default{timer(){x();}}