add webob to intersphinx list

With this change, we get hyperlinks for webob cross-references.
Merge pull request #942 from tshepang/webob

add webob to intersphinx list
make example links clickable, for convenience
Merge pull request #943 from tshepang/hyper

make example links clickable, for convenience
make example links clickable, for convenience
Merge pull request #944 from tshepang/hyper

make example links clickable, for convenience
Merge remote branch 'upstream/master'
give installation a colectomy; give it headings;