Update CONTRIBUTORS.txt

raise error and debug log for no geometries found case

Change "NS" to "KMLNS" for legibility and consistency

Protect AttributeError from data element without value #38

https://github.com/cleder/fastkml/issues/38

+ Contributors update ;)

Interactive usage examples added as standalone scripts - Thanks a lot :-)

Two files were added in examples folder, with a non-interactive version of the examples from usage guide.

Adding examples folder

Protect AttributeError from data element without value #38

https://github.com/cleder/fastkml/issues/38

handle coordinates tuples which contain spaces

Coordinates can be any number of tuples separated by a
space (potentially any number of whitespace characters).
Values in tuples should be separated by commas with no
spaces. Clean up badly formatted tuples by stripping
space following commas.

See reference: https://developers.google.com/kml/documentation/kmlreference#coordinates