updated docs to reflect recent changes.

updated docs to reflect recent changes; also bumped version to 0.20.

bumped version to 0.19; also added a "Trouble Shooting" section to docs.

reindexed a test case.

bumped version to 0.18.

bumped version to 0.17.

upgraded the version number to 0.16.

updated docs to reflect recent changes.

sync'd docs from the nginx wiki site.

removed code for nginx older than 0.8.12.