Started documentation of MassSpecDataSet with lots of code cleanup.

minexpert/gui/AbstractPlotWidget.cpp

minexpert/gui/ColorMapWnd.cpp

minexpert/gui/DriftSpecPlotWidget.cpp

minexpert/gui/DriftSpecWnd.cpp

minexpert/gui/MainWindow.cpp

minexpert/gui/MassSpecPlotWidget.cpp

minexpert/gui/MassSpecWnd.cpp

minexpert/gui/OpenSpectraDlg.cpp

minexpert/gui/TicChromPlotWidget.cpp

minexpert/gui/TicChromWnd.cpp

minexpert/nongui/MassSpecDataFileLoaderBrukerXy.cpp

minexpert/nongui/MassSpecDataFileLoaderDx.cpp

minexpert/nongui/MassSpecDataFileLoaderMs1.cpp

minexpert/nongui/MassSpecDataFileLoaderPwiz.cpp

minexpert/nongui/MassSpecDataFileLoaderSqlite3.cpp

minexpert/nongui/MassSpecDataSet.cpp

minexpert/nongui/MassSpecDataSet.hpp