reorganized the files

notebooks/.ipynb_checkpoints/HDF5Widget-checkpoint.ipynb

notebooks/.ipynb_checkpoints/HDFViewerDemo-checkpoint.ipynb

notebooks/HDFViewerDemo.ipynb

src/viewers/MplDataViewer.py

src/viewers/MplDataViewer1D.py

src/viewers/MplDataViewer2D.py

src/viewers/MplDataViewer3D.py

src/viewers/__init__.py

src/widgets/HDFViewer.py

src/widgets/MplOutput.py

src/widgets/PathSelector.py

src/widgets/__init__.py