Improve error messages for slices

[ewoutkramer]

Here, the name of the element (Observation.value) is somewhere in the middle and repeated completely at the end.

[ERROR] Element is of type 'boolean', which is not one of the allowed choice types ('string','Quantity') (at [0].entry[2].resource[0].valueBoolean[0], element Bundle(http://example.org/StructureDefinition/DocumentBundle).entry.resource->Observation.value[x][@default])

Is this good enough? Just make an exception for slices? Everywhere?

[mmsmits]

I'll split this into two separate issues

[mmsmits]

Moved the other issue here:
#232

[ewoutkramer]

This is actually the "open" issue that you split up ;-)

[mmsmits]

ah oops

[ewoutkramer]

Wait, it all got mixed up. I'll close this one and update the other. So this one was about "slices".