Merge pull request #1 from jwuttke/master

Various modifications, in response to my own criticism
convert tables to PNG figures
The Design Principles section did not describe any of the principles!  Pull that content from the User Guide.
Removed unnecessary bbl file
Merge branch 'master' of ssh://github.com/nexusformat/communications

Conflicts:
	2014/csipaper/nexus14aip.bbl
* add changes indicated by Herbert Bernstein
* change "x-ray" to "X-ray" per IUCr usage (e.g., http://iucr.org)
changes from Herbert Bernstein
Added .gitignore file
Changed affiliation of Eugen Wintersberger
Added postal code of Garching.
@Eugen: to the best of my knowledge, prefix "D-" is declared obsolete by Deutsche Post.