The shared approach results in conflicts if the generated class is used
in ATxCommon which is imported in the other projects. This way we can
use the symbols defined via ATxCommon in all depending projects.

The downside is that it slows down the build-process a bit as every
build from a project depending on ATxCommon (read: all others) will
change the generated code and thus force a re-build of ATxCommon and
the project itself. Since building the entire solution is still just
a matter of seconds, that's a fair trade-off.

See https://stackoverflow.com/a/10334095/2018314 for details on sharing
resources among multiple projects in a solution.

Refers to #13, #17

This is required for using the latest version of RoboSharp and also
offers newer C# language specifications.

Refers to #15

Following the new naming guidelines.

All projects (and namespaces) should start with an "ATx" prefix, having
a capital "AT" and a lowercase "x".

Since we have more to share between the applications than just the XML
wrappers, this is the location to keep common classes and methods.

Refers to #2

Fixes #22

Note that this only adds the new class library, it does not yet adjust
the existing service code to use it!

Refers to #21

Corresponds to "autotransfer-v1".