flag bad measurements and exclude from output

[twollnik]

There should be an option to "flag" bad measurements. When the processed data is downloaded, the flagged measurements should be excluded from the downloaded data.

[thomas-muench]

To implement this, we suggest, for the time being, to add a button "Flag bad measurements" on the process-data page. Clicking this button will output a table with sample number and name, water level, isotope standard deviation (...) and a checkbox column.