ENH: Add new "project describe" API task

Also add "status" field to "project list" task response
ENH: Add new client site API functions
ENH: Add new CDash info API functions

This required renaming a CDashAPI class to WebAPI
ENH: Add new "build list" API task
ENH: Add new "build describe" API task
ENH: Add new "build diff" API task
ENH: Add new "build tests" API task