Force all parameters and root datasets to be 3D.

Default dimensions to 1 and indicies to 0 for unused
axes.
Now we only save 3D arrays ONLY 3D.
Merge branch 'master' of github.com:Xarthisius/fgdfio
Merge branch 'master' of github.com:Cadair/fgdfio
Start work on a dataset reader
Add read to dataset_io
Read_dataset seems to be working, change write example to save 3D
dataset
allocating array is going mad.
Modified read routine to not use auto type select.
Writer tweaks.
Improve README and update the gdf_datasets module.
dataset read interface public name
Add a parallel write example.
Towards dataset parallel write.
dataset parallel write seems to work, example not so much.
Updates to parallel read / write.

Both now work and read validates write.
Merge pull request #6 from Cadair/master

More improvements, including parallel i/o