Fixed the areawidget javascript to use the new ajax syntax.
Corrected dependencies in docs and setup.py.
Removed dependency links in favor of pip install -f.
See also: https://caremad.io/blog/setup-vs-requirement/ and the discussion in the pip mailing lists about the deprecation of dependency_links support.
Merge branch 'dependency-fixes'
Merge branch 'master' into doc-improvement

Conflicts:
	docs/guides/installation-and-setup.rst