modified the module to be based from externally set SERVER/ENDPOINT vairables.  Added some documentation.

 The proc service endpoint is changing.  I pulled the server/endpoint information out of the methods and made them
 module level variables. These module levels variables are  over-ridden by environment variables from callers shell.

 These changes were needed to support migration of CANFAR to OpenStack.
made the cantop use the commonparser

vos.commonparser is where we put standard options like --verbose.  Also, this cleaned this up a bit.

cantop is still a bit weird as some of the customization is in the module and some of it is in the script...
Made the DELAY and RATE also be custom settable. And made call to vos.Client more generic.