Combine weather indoor/outdoor data

Handled similar to multiple columns for multiple scintillators
Update dataset preview and add downloading

More show data button to datasetlist
Add download button, to download the csv
Ad column to show numbe rof events in datasets
Fix initial date and randomize first selected station

Change timepicker addon to use 'setDate' from jQueryUI
Add download header to dataset list table
Remove helptext from date, the datetimepicker formats it correctly