added ssl_version to connection parameters
Put a guard in to check that the SSL version is sensible.

This is checked in before being set in the connection class.
Add SSL version support to the command line tools.

To continue to mirror curl options for the SSL parameters the different SSL
versions can be selected with the same switches: -1, -2 or -3.
Add a new example connection parameter class for SSL version 3.

Simply sets the SSL version to 3.
Describe the connection parameters in more detail.
Merge branch 'ssl-version' into rh/2.4.2

* ssl-version:
  Describe the connection parameters in more detail.
  Add a new example connection parameter class for SSL version 3.
  Add SSL version support to the command line tools.
  Put a guard in to check that the SSL version is sensible.
  added ssl_version to connection parameters