Unbundle tzinfo gem

Sadly, unpacking tzinfo into vendor gems breaks Rails' time zone
support and gives the following error when trying to access
admin/settings:

  uninitialized constant TZInfo::Timezone::TimezoneProxy

So we're going to instruct the user to install this gem using 'sudo
rake gems:install' for now.

RAILS-2.2-TODO.txt

@@ -4,7 +4,12 @@ release based on Rails 2.2.
 / Try to upgrade to gem version of coderay
 / Fix TZInfo to work again
 / Security audit--see below
-  Fix script/generate
+/ Fix script/generate
+
+  Figure out why Mephisto won't work unless tzinfo is installed
+  Fix two intermittent comment failures in mephisto_controller_spec
+  Follow up on courtenay's BlueCloth patch
+
   Make sure we know what's up with plugins
   We need to review our TODO comments
 

public/install.html

@@ -43,6 +43,13 @@ <h2 style="margin: 10px 0">Installing Mephisto</h2>
             freeze edge rails: <code>rake rails:freeze:edge</code></p>
             <br />
 
+            <p>You will need to install the <code>tzinfo</code> gem using
+            the following command.  For some reason, unpacking
+            the <code>tzinfo</code> gem into <code>vendor/gems</code>
+            breaks Rails' time-zone handling.</p>
+
+            <pre>sudo rake gems:install</pre>
+
             <p>You can visit the <a href="http://mephistoblog.com/docs/setup">Mephisto install documentation</a> on the site to get the most recent content, 
               however for the impatient, here's the quick setup guide:</p>
             <br />