This applescript will turn the option off. Make sure that access for assistive devices is turned on, which is found in Universal access.

tell application "System Preferences"
    set current pane to pane "Trackpad"
    tell application "System Events"
        tell process "System Preferences"
            if window 1's tab group 1's checkbox 3's value is 1 then
                tell window 1's tab group 1's checkbox 3 to click
            end if
        end tell
    end tell
    quit
end tell

Finished dictionary

I found a Wiki parser that cleaned much the Codex exported XML, then did some extra clean up using TextMate regex search/replace and managed to build a decent dictionary:

^{Minor issues will be found as the Codex is a collective effort, and formatting may vary from article to article.}

I put the source files and finished .dictionary file on Dropbox:

• PHP files to build a custom XML from WordPress Codex exported XML
• Project files to build the dictionary
• Final dictionary file, put on ~/Library/Dictionaries ^{_{Mirror on Google Drive (zip contents viewable).}}

Initial steps

I was able to create a very rough Codex dictionary using this resources:

• Following the steps to install and make a dictionary described in How can I create a dictionary for Mac OS X?

• A sample XML file from the tool SQL to Apple Dictionary

  <?xml version="1.0" encoding="UTF-8"?>
  <!--
          This is a sample dictionary source file.
          It can be built using Dictionary Development Kit.
  -->
  <d:dictionary xmlns="http://www.w3.org/1999/xhtml" xmlns:d="http://www.apple.com/DTDs/DictionaryService-1.0.rng">
  <d:entry id="ldap" d:title="LDAP">
          <d:index d:value="LDAP"/>
          <h1>LDAP</h1>
          <p>Lightweight Directory Access Protocol</p>
  </d:entry>
  <d:entry id="midi" d:title="MIDI">
          <d:index d:value="MIDI"/>
          <h1>MIDI</h1>
          <p>Musical Instrument Digital Interface</p>
  </d:entry>
  <d:entry id="xml" d:title="XML">
          <d:index d:value="XML"/>
          <h1>XML</h1>
          <p>Extensible Markup Language</p>
  </d:entry>
  </d:dictionary>
  

• A PHP script to convert the exported Codex XML file to conform with the sample file. Here's a Google Drive file with the resulting XML (70 thousand lines) and a Gist with the conversion script.

This is the result:

As can be seen, the biggest issue is to convert WordPress markup language into HTML.