Display intensities with frequencies

- Two columns in frequencyList
- Display intensities in %
- Implement copy frequency table
- Rename frequencyList -> spectrumTable
- Enable save spectrum data only when data exist
Reorder import headers
Add 'Generic Output file format' format
fixup rcc rule in Makefile
Fix axes clearing
Display svg in main window
canonical smiles as title
mpl toolbar is QToolBar