mereged in old patches for issue #225
This is a path submitted by barry.wardell@gmail.com to the google code site on issue #225 with the following message:

'I have tested these patches with the latest mercurial version and can confirm that they work fine for me.
I also find the attached patch for the high-level interface convenient.'

Shoved into git by Thomas Caswell <tcaswell@gmail.com>
re-factored prop list classes a bit.

The classes for data set creation (`PropDCID`) and group creation
(`PropGCID) now inherit from the object creation class (`PropOCID`),
which has the code for dealing with `H5P*obj_track_times`.
and required changes to pxd file
Added unit test for disabling track_times for data sets
fixed comment on test function
Add low-level interface to get_vfd_handle
Rename get_vfd_handle to get_descriptor, fix issues and add two tests
Merge pull request #271 from tacaswell/issue_225

Issue 225 (disable mtime tracking for datasets)
Fix old bytes/string glitch exposed by mtime tests
Fixes for remaining comments
Merge pull request #300 from tovrstra/vfd_handle

Add low-level interface to get_vfd_handle
added iterate to LinkProxy
Add list-based iteration to GroupID
Fix off-by-one bug in h5ds (issue 304)
Use LooseVersion for checking cython version (issue 298)
Add errors table entry for bad references
Add test for ValueError in response to invalid ref (issue 294)
Merge pull request #313 from andrewcollette/issue_298

Use LooseVersion for checking cython version (issue 298)
Add test for issue 310