v0.2.9

Changes since the v0.2.8 release:

• fix for numpy deprecation warning - use frombuffer not fromstring
• support broadcast for dset
• fix for external links with relative paths
• fix for creating dataset with initial data
• fix for create_dataset with **kwds args
• return dset.chunks as tuple not list (for h5py compatibility)
• several fixes that improve dimension scale functionality and h5py compatibility