Merge branch 'release-0.2' into develop
REL: Bump version number to 0.3 and mark as development version
DOC: Flesh out install instructions and add link to tutorial
DOC: Update API documentation to standardize display of units
DOC: Include developer docs generated by gitwash
DOC: Adjust the documentation structure to get the correct page order
DOC: Label docs as docs for release 0.2.0
DOC: Update information for PyPI
REL: Start basic notes on the release management process
DOC: Add note on gitwash to the developer docs
DOC: Add sponsor logos to online documentation
DOC: Add reference to South Africa soil moisture paper
DOC: Forgot to add HESS reference to setup.py long description
DOC: Add note that windows users only need to install using one method
DOC: Add note about Matplotlib being an optional dependency
REF: Remove unused imports from model core
REF: Remove unused imports from parameter_utils module

In addition replace the following:

* Use numpy.ones() directly instead of scipy.ones()

* Use numpy.ma directly instead of importing via matplotlib.numerix.ma
REF: Remove unused imports from results_analysis

In addition:

* Replace scipy.zeros() with numpy.zeros()
BUG: Use correct package name in imports
BUG: Replace use of deprecated scipy.io.write_array() with numpy.savetxt()