The ssl cert check will now respect the http and https proxy
environment settings. The url may also have the username/password
embedded, in which case basic auth will be used to connect to the
proxy server.
Fixes#7413
Previously, the function checked only for a single CA root cert, however
some distributions may have multiple certs in a directory. This will now
try any .crt or .pem file contained within several common paths for
each platform.
Fixes#6412
* Adds another module utility file which generalizes the
access of urls via the urllib* libraries.
* Adds a new spec generator for common arguments.
* Makes the user-agent string configurable.
Fixes#6211