bzr-sloecode Installer for Windows

There's now a basic installer for the bzr-sloecode Bazaar plugin for Windows. It currently does the following:

1. Installs the plugin to the right place.
2. Sets the SLOECODE_SERVER environment variable to whatever you want.

There are a number of aspects that require improvment however:

1. It doesn't check that Bazaar is installed first.
2. It doesn't ask if the user wants to install the plugin for everyone or just the current user. Currently the SLOECODE_SERVER setting is system-wide, which requires admin permissions to set.
3. No validation on the Bazaar server address.

...So it's a work in progress! Patches are more than welcome. You can grab the installer from the bzr-sloecode launchpad page.