StatusCodeException error handler

[quantombone]

So those 400 errors thrown from VMXserver.go get turned into 500s.

StatusCodeException now cleans up the lock, so there is no more deadlock. The big problem was already solved.

But the error message still reveals information about the underlying port...
{"error":"StatusCodeException (Status {statusCode = 400, statusMessage = "Bad Request"}) [("Date","Wed, 04 Feb 2015 22:31:05 GMT"),("Content-Length","56"),("Content-Type","text/plain; charset=utf-8"),("X-Response-Body-Start","{ \"error\": 1, \"message\": \"Cannot Show compiled model\" }\n"),("X-Request-URL","POST http://127.0.0.1:51211/command")](CJ {expose = []})"}