added spaces around math operators
data exampe & attempt to fill legend boxes
scale_fill_identity doesn't work either
replace geom_point() legend symbol with imitation of that of geom_bar()

learned from http://stackoverflow.com/a/27404156/4341322
added file selection notification
instruct user to install packages & removed checks
started export & import of known data
attempting to iteratively append new rows below existing data

appends incorrectly as new columns
injection of new data works :-)
Merge branch 'import-export-existing-raw-data' into develop
hot-fixed check for old data & corrected indentation
more files required for good demo, but unsure if OK to publish
resolved merge conflic
Merge branch 'master' into develop

Conflicts:
	README.md
Merge branch 'develop'