PR 504 not merged yet

Author: effigies

Changelog

@@ -39,9 +39,8 @@ Enhancements
 * Support for alternative header field name variants in .PAR files
   (pr/507) (Gregory R. Lee)
 * Various enhancements to streamlines API by MC: support for reading TRK
-  version 1 (pr/512); improved error messages (pr/504); concatenation of
-  tractograms using `+`/`+=` operators (pr/495); function to concatenate
-  multiple ArraySequence objects (pr/494)
+  version 1 (pr/512); concatenation of tractograms using `+`/`+=` operators
+  (pr/495); function to concatenate multiple ArraySequence objects (pr/494)
 * Support for numpy 1.12 (pr/500, pr/502) (MC, MB)
 * Allow dtype specifiers as fileslice input (pr/485) (MB)