Disabled radio buttons at initialisation, to stop crashing
Histogram plotting ok for now
Auto-scale Y axis on histogram
Sorted initialisation of radio buttons on histogram
Write histogram data to file
Do not add counts to the histogram if there were error flags
Clear histogram to stop crashing on refresh
Deleted code to test histogram
Stopped user from creating spectrum with blank name, updated comments
Use standard library to resize arrays instead of my own function

Method extendArray in SpectroscopyViewerForm has been deleted
Fixed calculation of frequency in fileHandler
Fixed adding data to existing spectrum
Merged functions to update & create histogram (in spectrum class) into one
Fixed bug with maximum histogram size
Fixed bug with adding data from multiple spectra to histograms

Needed to copy over every element of the arrays, cannot just set arrays equal (reference type!)
Enabled opening multiple files. Put in some safeguards against crashing.
Added 'Notes' section to metadata. Tested opening file with metadata (success!)