Changed spectrumSelect form to handle multiple spectra

Not quite finished
Need to redesign
Redesigned to use combo boxes. Need to work out how to show them!
Combo boxes no longer appearing, not sure why
Revert "Combo boxes no longer appearing, not sure why"

This reverts commit 6a119b0189d43e4c49808ef93ee50cde98aac35f.
Multiple combo boxes created