Add DLSw leak capture module for CVE-2014-7992

Note: I have a zip file that contains a full setup to test for this vulnerability.  It has 2 Win VMs and a GNS3 configuration with 3 routers to enable testing. I would be happy to share. Otherwise you need to build a working DLSw setup to test.
@jhart-r7 so, on our test systems and within our vulnerable client networks the answer is yes, if the target Cisco router emits anything on TCP port 2067, then it is vulnerable. We have an email out to Cisco PSIRT's team requesting confirmation of this behavior.