doc: bumped version to 0.30.

doc: bumped version to 0.29; stated that we work with nginx 1.7.10; b…

…e clearer about the connection pool configurations.

doc: typo fix from javasboy in openresty#27.

doc: bumped version to 0.27 and updated other stuff.

doc: bumped version to 0.26; also stated that we work with nginx 1.5.11.

documented the new feature in srcache_store_skip.

bumped version to 0.24.

updated docs to reflect recent changes.

bumped version to 0.22.

updated docs to reflect recent changes.