Patch tested by compiling with `__attribute__ ((format (printf, 2, 3)))`
applied to `cmd_results_new`.
String usage constants have been converted from pointers to arrays when
encountered. General handler format strings were sometimes modified to
include the old input string, especially for unknown command errors.
- added L_AUTO_FIRST/LAST instead of using explicit layouts.
- when switching between auto layout that don't share the same major axis, invert the
width/height of their child views to preserve their relative proportions.
