LCARS demo enhancements

[JoeStrout]

1. Find or make a more appropriate font (in two or more sizes), and use throughout. This page suggests that Helvetica Ultra Compressed would be the best match for the show.
2. Move the four current modules (File Manager, Clock, Calculator, and News) into separate scripts in a /sys/lcarsMods directory. When loading mods, search both /usr/lcarsMods and /sys/lcarsMods, allowing the user to add additional modules or replace built-in ones.
3. Consider adding some additional mods:
   a. Graph (plots 2D or 3D equations, optionally parameterized by t, u, and v)
   b. Environment (shows current weather info from some REST service)
   c. Planet Scan (shows map or 3D globe of the Earth, with pins on it showing where Mini Micro has been used in the last week)
4. Be sure to document how users can create their own mods, and consider rolling in any especially good ones into future Mini Micro updates (if the authors approve)!