use same window as help

[y]

If editing a vim file and a python file, opening help for vim file splits window for the help. Switching to the python. buffer and using ref to open help opens yet another split window for it's help so there are now 3 windows: the window with python, the vim help, and the ref window with the pydoc. I think it would make more sense for ref to use the same window as vim's help.