fixed the parse_legend function
fixed error when testing if errors are zero
fixed some errors with handling empty data sets
fixed error when given invalid file names (files that don't exist)
fixed error in parse_legend
added helper function which drops to an interactive shell
fixed error where user supplied x axis labels were being ignored
cleaned up unused entries in the global dictionary
rename main loop to clplot and moved initial data read to init function
added bare bones interactive mode
init now takes data and filenames by keyword
interactive function gets passed values for user to manipulate
'q' not exits interactive mode
if plot() is called while the interactive flag is still true, the plot will be shown instead of written to file
fixed error with dropping to interactive shell from interactive mode
added interactive command to load files
fixed bug when there are multiple blocks in a single file which need their formats deduced
refixed bug when trying to gues x-axis label from column headings
fixing up the handling of data and blocks in interactive mode
thinking about interactive data processing