data slice can live with less information

[jgrewe]

with this pr, the util::dataSlice method automatically fills in missing information (to some extent). That is: start, end, and unit values may be missing or incomplete. If less info is given than there are dimensions defaults are assumed:

• units are filled with the ones defined in the dimension
• start is set to offset (SampledDimension), first tick (RangeDimension), or 0 (SetDimension)
• end is set to point (SampledDimension, RangeDimension) or max index (SetDimension)

General rule: if information is provided, the first value given is assumed to belong to the first dimension the 2nd to the second, etc.

[jgrewe]

there are three remaining warnings under windows. one is a config warning (cmake) and the other two are deprecation warnings (which are intended) during tests, imho, we should keep the tests alive as long as the functions are part of the public API