update plugin urls to reflect official maintainers

railties/guides/source/3_0_release_notes.textile

@@ -59,12 +59,12 @@ The +config.gem+ method is gone and has been replaced by using +bundler+ and a +
 
 h4. Upgrade Process
 
-To help with the upgrade process, a plugin named "Rails Upgrade":http://github.com/rails/rails_upgrade has been created to automate part of it.
+To help with the upgrade process, a plugin named "Rails Upgrade":http://github.com/jm/rails_upgrade has been created to automate part of it.
 
 Simply install the plugin, then run +rake rails:upgrade:check+ to check your app for pieces that need to be updated (with links to information on how to update them).  It also offers a task to generate a +Gemfile+ based on your current +config.gem+ calls and a task to generate a new routes file from your current one.  To get the plugin, simply run the following:
 
 <shell>
-$ ruby script/plugin install git://github.com/rails/rails_upgrade.git
+$ ruby script/plugin install git://github.com/jm/rails_upgrade.git
 </shell>
 
 You can see an example of how that works at "Rails Upgrade is now an Official Plugin":http://omgbloglol.com/post/364624593/rails-upgrade-is-now-an-official-plugin

railties/guides/source/active_record_validations_callbacks.textile

@@ -744,7 +744,7 @@ Rails maintains an official plugin that provides helpers to display the error me
 
 h4. Installing as a plugin
 <shell>
-$ rails plugin install git://github.com/rails/dynamic_form.git
+$ rails plugin install git://github.com/joelmoss/dynamic_form.git
 </shell>
 
 h4 Installing as a Gem

railties/guides/source/debugging_rails_applications.textile

@@ -686,7 +686,7 @@ There are some Rails plugins to help you to find errors and debug your applicati
 * "Query Trace":https://github.com/ntalbott/query_trace/tree/master: Adds query origin tracing to your logs.
 * "Query Stats":https://github.com/dan-manges/query_stats/tree/master: A Rails plugin to track database queries.
 * "Query Reviewer":http://code.google.com/p/query-reviewer/: This rails plugin not only runs "EXPLAIN" before each of your select queries in development, but provides a small DIV in the rendered output of each page with the summary of warnings for each query that it analyzed.
-* "Exception Notifier":https://github.com/rails/exception_notification/tree/master: Provides a mailer object and a default set of templates for sending email notifications when errors occur in a Rails application.
+* "Exception Notifier":https://github.com/smartinez87/exception_notification/tree/master: Provides a mailer object and a default set of templates for sending email notifications when errors occur in a Rails application.
 * "Exception Logger":https://github.com/defunkt/exception_logger/tree/master: Logs your Rails exceptions in the database and provides a funky web interface to manage them.
 
 h3. References

railties/guides/source/form_helpers.textile

@@ -475,7 +475,7 @@ To leverage time zone support in Rails, you have to ask your users what time zon
 
 There is also +time_zone_options_for_select+ helper for a more manual (therefore more customizable) way of doing this. Read the API documentation to learn about the possible arguments for these two methods.
 
-Rails _used_ to have a +country_select+ helper for choosing countries, but this has been extracted to the "country_select plugin":https://github.com/rails/country_select/tree/master. When using this, be aware that the exclusion or inclusion of certain names from the list can be somewhat controversial (and was the reason this functionality was extracted from Rails).
+Rails _used_ to have a +country_select+ helper for choosing countries, but this has been extracted to the "country_select plugin":https://github.com/chrislerum/country_select. When using this, be aware that the exclusion or inclusion of certain names from the list can be somewhat controversial (and was the reason this functionality was extracted from Rails).
 
 h3. Using Date and Time Form Helpers