Add installation options to the installer

[1]

https://answers.launchpad.net/bzr/+question/91004 suggests that Bazaar can be configured to run in a portable way with some extra effort. Please modify the installer and add options for the installation type. I suggest to take the Opera (web browser) installer as a blueprint (see screenshot).

Added value:

-non-administrators can install the software for themselves
-portable installation can be chosen as another option
-no manual configuration necessary for the latter

It should be possible to run both Bazaar and Bazaar Explorer.

Difficulty level: Adding the feature should be easy and straightforward for Bazaar developers.