clarify context menu entry choice between cheetah and registry
Many users seem to get confused when asked to decide between
"Context menu entries" and "git-cheetah shell extension".
Since they want the context menu entries many will choose the registry
based ones since it explicitely talks about the context menu.
Lets talk about the same thing "context menu" and distinguish them by
calling them advanced and simple. To help existing users to recognize
these option from the previous installers mention the methods
(cheetah/registry) in brackets.
Signed-off-by: Heiko Voigt <hvoigt@hvoigt.net>