Mandatory selector support for event-based plugins

This page applies to Harlequin v13.1r0 and later; and to Harlequin MultiRIP but not Harlequin Core

All event-based plugins must support the following selectors:

D_SELECTOR_SUPPORT D_GET_IDENTITY D_GEN_BOOT D_PLUGIN_INITIALISE D_SECURITY D_LIB_SELECT D_GEN_SHUTDOWN D_EVT_GETHANDLERS