SimpleTag::units accepts empty string as valid unit
new method to get offset and count NDSize objects for simpleTags
documentation of positionToIndex
Test for util::getOffsetAndCount
Merge branch 'master' of https://github.com/jgrewe/pandora-1 into position_extent
bugfix in checkDimensions. Could not handle more than 1D, bad
implementation
add forceUpdatedAt to setter for units
implementation of offsetAndCount for dataTags, according tests
removed old-style casts with static_cast :-)
Merge pull request #211 from jgrewe/position_extent

Implementation of util methods that calculate offsets and count for positions and extents

LGTM