doc: various updates.

Author: agentzh

README.markdown

@@ -692,12 +692,12 @@ Alternatively, you can compile this module with Nginx core's source by hand:
 ```
 	You can fix this by pointing `python` to `python2`.
 * Download the latest version of the release tarball of this module from drizzle-nginx-module [file list](http://github.com/openresty/drizzle-nginx-module/tags).
-* Grab the nginx source code from [nginx.org](http://nginx.org/), for example, the version 1.7.10 (see [nginx compatibility](#compatibility)), and then build the source with this module:
+* Grab the nginx source code from [nginx.org](http://nginx.org/), for example, the version 1.9.7 (see [nginx compatibility](#compatibility)), and then build the source with this module:
 ```bash
 
-     wget 'http://nginx.org/download/nginx-1.7.10.tar.gz'
-     tar -xzvf nginx-1.7.10.tar.gz
-     cd nginx-1.7.10/
+     wget 'http://nginx.org/download/nginx-1.9.7.tar.gz'
+     tar -xzvf nginx-1.9.7.tar.gz
+     cd nginx-1.9.7/
 
      # if you have installed libdrizzle to the prefix /opt/drizzle, then
      # specify the following environments:
@@ -725,7 +725,7 @@ This module has been tested on Linux and Mac OS X. Reports on other POSIX-compli
 
 The following versions of Nginx should work with this module:
 
-* 1.9.x (last tested: 1.9.3)
+* 1.9.x (last tested: 1.9.7)
 * 1.8.x
 * 1.7.x (last tested: 1.7.10)
 * 1.6.x