dataio hdf5: add note about format problem with Offset
cli: add --update-metadata option

allows to update the metadata

also update the bash auto completion script
cli: support changing multiple attributes/metadata simultaneously

Especially handy for metadata as it's really just one function call
model: move MockComponent out from model to util.mock

Let's try to keep the model as small and clean as possible.
mock.MockComponent can be used anywhere where a fake component is needed.
model: add support for multiple parents for component created by delegation

Introduce the "creator" attribute: specifies the component that will be used for creation.

If a component has only one parent, it can be implicitly filled, so the current working microscope files are still valid.

Also add support for the CombinedActuator to components without .speed, to keep the test microscope file minimal.
doc: update microscope file specification for the "creator" attribute

also improve a bit the definition of some other attributes.