[Rd] Uninstall registry key the same for all versions (PR#10746)

[Gerhard Thallinger]

Hi Duncan,

>> I just wanna add a related suggestion that when you have multiple 
>> installations and you run "Unistall R 2.6.0" the first dialog
>> ('R for Windows Uninstall') you see says "Are you sure you want to
>> completely remove R for Windows and all of its components?"  This
>> message does not specify the version being uninstalled, so without
>> previous experience you certainly wonder if this is going to install
>> all of your R installations or just one.
>
> I'm just testing now, but I suspect Gerhard's suggestion of 
> specifying AppID will fix this too.

 Thanks for looking into this. I think setting "AppName" to the same
 as "AppVerName" (which includes the version number) should cover both
 Henrik's and my suggestion. 

Regards

Gerhard