Changed to download kre to temp folder, added -force command

Should fix:
#167 
#258 
#156 
aspnet/Home#61
aspnet/Home#41

Possibly some other dupes, I'll go through them all if we merge it.

That's the way all the else statements are in this file, I was following the style already layed out. I think is the way that Powershell is normally done as well, but could be wrong about that.

Do you want to change that?