Added scanconvert.h for unit conversion functions and made organizational changes to user functions in scanusr.h
Added configuration file to store calibration data.
Minor changes, cosmetic
Renamed 'scanconvert.h' to  'scancalb.h' to stay consistent with 7-8 letter filenames.
Modified build functions to take optional argument of a time pointer - for possible later implementation of nested build functions.
Minor changes, cosmetic.
Major changes to string handling in scan builder library.