Installation options

Currently the installer does some things without requesting
the user's permission and without offering a choice. It
would be nice to make it a bit more flexible. In particular:

- A desktop icon is created. Would be nice if the user is
asked whether such an icon should be created - even if
"yes" is the default answer.

- The product is installed in the "root" of the Start menu.
Would be nice if the user could specify where exactly in
the Start menu the product is to be installed. For
instance, the user might have already other anti-spyware
products in Start/Anti-Spyware and might want to install
the product there.

- The product is installed for all users (which requires
administrative privileges, I think). Would be nice if the
installer allowed the option to install the product only
for the current user.