Added support for SSL via connection string

The usage is 3 new optional parameters for a connection string:
1. `sslCipherSpec`: the algorithms used
2. `sslKeyRepository`: the location of the certificate repository (CMS type, kdb is the file extension, the path should not contain the file extension)
3. `sslPeerName`: the expected subject of the server certificate

Example usage:
`sslCipherSpec=NULL_SHA;sslKeyRepository=../../keyrepository;sslPeerName=CN=MQSERVER`

Is there a place to add documentation for that?

Implementation:
I initialized the environment variable `AMQ_SSL_ALLOW_DEFAULT_CERT` to true in order for the infrastructure to select the default client certificate from the certificate repository, otherwise it searches for certificate with the name webspheremq[current-windows-username] which is more brittle.

I had to change the transport to unmanaged to support SSL, I didn't see any implications for that.

I didn't add tests because the settings and connection creation parts weren't covered anyway and those were the only files I touched.