Spectrum File Support
Improve the support for spectrum file. One should be able to put a raw string like for the "value" attribute in the file directly:
300.0:0.1590986397149437,310.0:0.19393972058572118,320.0:0.23242903311147056910.0:0.010000000006943972,920.0:0.010000000002529126,930.0:0.010000000000902915,990.0:0.010000000000001228,1000.0:0.010000000000000382