Change sys.path hack, prefix dev-tree working dir.

I am close to moving __version__ elsewhere in order to avoid that mess
Refactor report creation into rapport.report.create_report

Results into a much cleaner CLI class. Maybe it may make sense to even
create a Report class in the future.
Drop sys.path hack
Support globbing reports in the "delete" command

Makes deleting multiple reports simpler.
Allow to edit generated work reports
Re-arrange report commands in a CRUD way
Re-structure e-mail command(s), i.e. no sub-sub-parser

Was a bad idea, it's better to have more verbose command names.
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