minor: add newline at the end of file
add list of neighbours used for each node

not rocket science, but useful for text file export of coefficients.
add spline coefficient text exporter

basically a code to generate a CSV file with the coefficient information
for a given interpolator.
spline coefficients writer: use CR+LF for csv files
make sure csv file contains a matrix

i.e. fill up missing coefficients with zeros when needed
add archives and CSV values to gitignore
issue#6 solved

use argparse in get_spline_coefficients.py, and make it executable.
now it can be called from a shell script or whatever.
if someone wants the polynomials for other datasets, they can simply
copy paste/import the write_coefficients function from this example.
Merge pull request #8 from idies/develop

Develop