chore(dream): re-export dream-pure library

[glennsl]

Using the template preprocessor assumes dream-pure is re-exported, which it won't be if implicit_transitive_deps is disabled in the consuming project, unless the library is explicitly re-exported. This does that.

For more information:

• Documentation for re_export
• Documentation for implicit_transitive_deps
• An example of someone likely tripping over this on Stack Overflow

[aantron]

Thanks! This was actually an oversight. The templater should have been emitting Dream.html_escape. Probably left over from some refactoring. The templater uses the Dream module directly in other code it emits. I tested the templater against a version of example 7-template with (implicit_transitive_deps false) and it now works.

[samoht]

I think this breaks MirageOS support, as now you need to depend on dream when using eml files

[aantron]

@samoht As I understand it, dream-mirage already depends on dream. Do you mean something extra?

[samoht]

It doesn't depend on dream in the dune file

[aantron]

@hannesm, @dinosaure, could you comment on whether this indeed breaks Mirage? I'm ready to revert 9938850 and merge in the original commit here, if needed.