New flagged value masking behaviour
The following changes to the masking of flagged values are implemented:
- we only reinject the masked values at positions that are flagged before and after the call to (test-)function
- if a (test-)function changed the index of a
data
-column (either its shape or any number of timestamps), the reinjection of masked values is skipped
Not the most elegant solution, but a (hopefully) a working one. Any suggestions are welcome @luenensc and @palmb .
This should close the following issues: #66 (closed), #61 (closed), #58 (closed)