Add new form spectrumSelect

Changes not completed yet - needed to commit anyway
Added form spectrumSelect

Opens when file is selected, gives the option to add file to existing or new spectrum
Finished spectrumSelect form
Fixed bug with index of list items in mySpectrum

Also changed from form.Show to form.ShowDialog - so that the program will wait until the form has been closed before continuing
Default to create new spectrum
Adding data to existing spectrum now works!
Laid out most of main form, still need to do RF frequency control in live section
Adding ability to select which spectrum to add to for all interleaved data. Not complete

Need to make sure ordering is correct to avoid errors
Added code to manage ordering of spectra in array

So that items are added in the correct order when List.Add is used
Fixed bug in the ordering code
De-interleaving as soon as data is read by fileHandler

Data is then stored in an array of lists instead of a single list
Deleted file "New ideas.txt"

Ideas have been implemented already
Fixed bug with initialisation of arrays in fileHandler
Debugging interleaving
Finished main form designer
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.