Added support for hdf5 format in Storage class.
Added a first example for handling hdf5 files.
First draft of elwise reduction design doc
Add some example reduction type signatures that result from sum calls
Expand on the type signature matching for reduction
Added a small tutorial for handling HDF5 files in manual
Actually exit() when no pytables is installed. Name of sample a bit more meaningful.
Moved sections of HDF5 and BLZ from tutorials to data_sources chapter
Merge branch 'hdf5_docs' of github.com:FrancescAlted/blaze into hdf5_docs
Rephrasing the requirement message
Fix typo, add list of links to top of execution document
Merge pull request #136 from mwiebe/reduce-design

reduce design/test document
Merge pull request #135 from FrancescAlted/hdf5_docs

HDF5 DataDescriptor docs and examples