(v13) Input plugin startup

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

On some platforms, memory can be reclaimed by removing the input plugin code. If this happens, the state of the plugin will be preserved, so that the unloading and reloading of plugin code will not inter‐ fere with the operation of the plugin.