Registering a Design Editor Plugin

To make a plugin available for installation on an application window:

Register the plugin by using deRegPlugin. Specify the plugin name (appName) and the class and superclass names (className and superClass) which implement the plugin.
After a plugin is registered, use the appName and className to uniquely identify the plugin. For example, to register My Plugin so that it can be installed on all applications associated with view type schematic, such as VSE and VSE XL applications, use the following code:
```
deRegPlugin(
 "My Plugin"
 'MyPlugin
 'DEPlugin
 ?appTitle "My &Plugin"
 ?pluggableViewTypes '("schematic")
 )
```
Retrieve a copy of the registration information of a plugin by defining deGetAppClassInfo. This function returns a copy of the registration information as a Disembodied Property List (DPL) associated with an application. For example, the following code retrieves a copy of the registration information associated with My Plugin:
```
(deGetAppClassInfo "My Plugin")
```
```
 =>
(nil appType plugin
appName "My Plugin"
className MyPlugin 
superClass DEPlugin
bindkeys nil
 "" 
pluggableMainApps nilpluggableViewTypes '("schematic")
shortDescription ""
)
```

However, a limitation with deRegPlugin is that the function issues a warning if:

A class symbol is already used by an application.
A plugin application name is already registered, or used as an application tool name, such as "&ADE L".