Screen Saver API: Changes

The following header file(s) have changed between 3.0 and 3.1

**Table 3:** screensaverplugin.h
Type	Class	Change
New enum value		`TScreensaverIndicatorIndex::EScreensaverIndicatorIndexAmPm`
New enum value		`TScreensaverEvent::EScreensaverEventPreview`
New enum value		`TScPluginCaps::EScpCapsPreviewNotification`

**Table 4:** screensaverpluginintdef.hrh
Type	Class	Change
New enum value		`TScPluginCaps::EScpCapsPreviewNotification`
New define		`KScrPluginCapabilitiesPreviewNotificationStr`