BNL license text approved by Dorene.

To be merged to each diffpy package repositories.
Fix inline verbatim quotations in rst format.
Chris is the main author.

Add link to contributors on GitHub.
Remove obsolete makefile.

This resolves #5.
Shorten license description.
Remove relics from svn keyword expansion.
Use exact name of Columbia Trustees.
Use lowercase pyobjcryst equal to Python import name.
Add missing headers for unit test files.
Update Columbia trustees name.
Rename old LICENSE.txt --> LICENSE_DANSE.txt.
Add BNL license file.

This resolves #6.
Merge branch 'license' from diffpy-release.