Add support for Cli_ReadMultiVars

This change add supports for the Cli_ReadMultiVars function.  I have also included an example.

This is my inexperience showing, I did not know you could do that.  I have not done much work in python before and this is the first time I have tried to work with a C library from python.  I will try to find some time to experiment with the method you mentioned. 

While my implementation of Cli_ReadMultiVars works, I think it could be made much easier to use.