* [480x272] Fix static initialization order problem with Layout, Theme, & Widget factories.
* [480x272] Fix return from drawTimerMode().
* [480x272] Remove use of macros for registered Layout, Widget, & Theme class lists; remove extern declarations (cosmetic).
* [480x272] Convert Layout and Theme registry to dynamic lists (still max. of 10 each);
Hide indicator arrow when user is at start/end of available widgets in spinner UI;
Add some sanity checking to pointer usage in screens_setup;
Add an (arbitrary) limit of 20 Widgets;
And a line break! :)
