Disable all warnings (∵ given/when).
latex2unicode: Enable use of environment variable DEBUG.
L2U/Constants.pm: Add log.
t/frac.t: Test for proper boxing with combined characters (not really frac-specific).
Update author information.
L2U/Common.pm: Add common module; override length().

All latex2unicode modules need a modified length() routine for proper
combined character count.
latex2unicode: Use L2U::Common; more D()'s.
L2U/Handlers.pm: Use L2U::Common.
t/*: Update all tests to use Unicode::Normalize.

Rampant code duplication.  Watch me care.