PluginManager

Plugins are installed in the <projectpier_root>/application/plugins folder.  Currently, MVC files are installed in the <plugin_name>/application subdirectory of the plugins folder.  Library, helper, and language files are, however, installed in subdirectories of the plugins folder instead of being located under the plugin's subdirectory.  This should probably be fixed so that all files for a particular plugin are installed inside that plugin's subdirectory.

The plugin architecture supports both actions and filters.  The difference between these is a matter of input; all actions on the same hook receive the same input regardless of order, filters receive modified input from previous filters on the same hook.  Five actions and one filter are currently defined:

I. Actions
 a. add_dashboard_tab
 b. add_administration_tab
 c. add_my_account_tab
 d. add_project_tab
 e. project_overview_page_actions

II. Filters
 a. tabbed_navigation_items

Currently lacking from the PluginManager is the ability to define, manage, and control permissions on the plugin.  This is, perhaps, the most severely lacking feature of this patch.