Test suite

To my surprise we are still in a good shape w.r.t. potential regressions.

This pull adds a couple of scripts that checkout recent versions of testsuites if not checked out yet and run the tests against dmdscript console runner. Sadly no `.bat` version I'm no ninja in Windows scripting. It's just a couple of lines though.

Here is the summary of Sputnik testsuite for ECMAScript v3 (2011):
```
=== Summary ===
 - Ran 5293 tests
 - Passed 4818 tests (91.0%)
 - Failed 475 tests (9.0%)
```
Not bad!

Though here is more recent version (evolved from the same project) for ECMAScript v5.1... (2014):
```
=== Summary ===
 - Ran 11208 tests
 - Passed 4840 tests (43.2%)
 - Failed 6368 tests (56.8%)
```
Obviously nothing in DMDScript knows of v5.1 standard. Lots of work to do.
But at least now we can refactor with relative peace of mind by checking against the test-suite. 
I suggest to use the older sputnik for now.