updates tomography tool routines; adds MAX_STRING_LEN parameter for strings
updates configuration and m4/ scripts (fixes configuration with CUDA and intel ifort compilers)
updates smoothing tool and adds mesh geometry to values_from_mesher.h
fixes parameter output to values_from_mesher.h file for mesh geometry (avoids line breaks)
updates interpolation tool and rules.mk in src/tomography
adds difference tool to src/tomography