restydoc: updated the bundled version of the LuaJIT docs to the latest.

formal release 1.13.6.1.

bumped version to 1.11.2.5; also updated tests to reflect recent chan…

…ges.

bugfix: applied nginx's official security fix for an issue in the ran…

…ge filter (CVE-2017-7529).

formal release 1.11.2.3.

bumped version to 1.11.2.2.

bumped version to 1.11.2.1.

updated tests to reflect recent changes.

bugfix: applied the patch for nginx security advisory (CVE-2016-4450).

also bumped version to 1.9.7.5.

release 1.9.7.4.