I am looking for a bugtracker that can be used to register changes (bugfixes, features, updates, deletions) for the current set of items customers are working with.

In this case it is mainly scripts (pascalscripting running inside a delphi program) that are stored in a database from the customer where I have all scripts stored in SVN.
If the customer needs some extra features in a part of those scripts there cannot be said that they use a new version of the whole set of scripts (atm 1000+ files containing scripts)

So how can I enter the requests of the customer and how can I show the customer release notes if one cannot speak of a release at all ?
Something else that is an issue atm, is how is the customer able to see what version from the release notes they are running and where they are running it (testserver / productionserver etc)

We also are doing some php scrips that should be tracked in about the same way, with the exception that we use it for integration into our default software that does have versions, but if those php scripts are changed there is no new version for this default software it is integrated into.

We use Mantis atm for other projects in our company, so if it can done somehow in Mantis it would be great, but if we need another bugtracker its no problem as well.