more systematic treatment of loadmodules=

[kohlhase]

For every sTeX environment that has a title= attribute, we have the problem that we often want to

• use semantic macros in the title, but
• use the current group induced by the environment for the \usemodule.

The problem is aggravated, if the title is exported into e.g. the table of contents or such things; e.g. for sfragment and assignment.

We used to have the uses= attribute e.g. in sproblem, e.g. in MathHub/MiKoProblems/GenCS/source/machines/mod/VM-divider.en.tex, which has

\begin{sproblem}[uses={[MiKoMH/GenCS]{machines/mod?VM-imperative}},
  title=Divider in $\VMlanguage$]

which specifies a \usemodule that is executed before the title= is executed.

We need something like this