Added automatic temperature fitting
-graph windows show the temperatures in the upper left corner
-fitting is performed after every change in roi or data_file
Changed ROI selector:
changed update funtion so that it can handle different sizes of images while loading new files
-this includes automatic updating of the roi limits (checking if they exceed the limits of the current image)
ImgData Class now also supports 1-dimensional data a.k.a. spectrums
Made the T_Rax_Roi selector a singleton