Passes the window width/height as the requested geometry to lde at startup.
Since we control the directory structure of the file-system, we can pass the
known fixed location of the Medley directories in the MEDLEYDIR environment variable.
Sets up the NetHub host as localhost - not currenty functional, but a WebSocket
server could be added to communicate with the NetHub gateway to enable local
networking from the browser version of Medley.
Moves the full.sysout from the root of tle system to /medley/loadups/full.sysout,
adds /medley/lispusers/BACKGROUND-YIELD.LCOM and an Emscripten/WAsm specific
site init file at /usr/local/lde/site-init.lisp
Adjusts options so that the options are in the correct place for the
compiler and loader.