rmcgibbo/mdtraj — pull request #531 by kyleabeauchamp (2014-08-11 17:11:30+00:00)
Title: Write REMARK header indicating MDTraj in output PDB files.

Works on my machine, but need to double check Travis for Py3K.

```
diff equil.pdb equil2.pdb
0a1
> REMARK 1 CREATED WITH MDTraj 0.9.1.dev-6803a26, 2014-08-11
```