Inclusion of Google Apps Single Sign-On

Continuing the discussion from #690224: Offering to take over Google Apps Authentication.

@cyberswat: I've just installed your module and have some questions regarding the "look & feel" of the module:

1) Would you like me to add the code to the google_auth.module file or should I use an .inc file? (I'd prefer the latter.)

2) The users need to configure at least three things: a) the Google Apps domain name, b) the location of the public key and c) the location of the private key. These should of course not reside inside the module's directory. Should I go ahead and create a settings page for that or should users hard code that information? (I prefer the first, but in the case of hard coding, we should create a separate settings.inc-new file that users have to remain to settings.inc so that it's not overwritten on updates.)

3) License: I see that FSF refuses to accept ASF license v2 as a compatible licence, based on grounds (patent revocation, indemnity) that do not even affect the Google code I use. If this means that I cannot include my modified files in the project, then including the SSO functionality doesn't really make sense as users would have to change too much source code. The best solution would then be to offer this "sub-module" separately (e.g. on Google Code) and include instructions for users on how to download and include it into the project - just as projects as fckeditor, getid3 etc. do it. So how do we proceed in this regard?