latex2unicode: Minor beautification; comments.
L2U/Constants.pm: Reenable cos and sin; add a few missing entries.
latex2unicode: vpad() now takes alignment argument.
latex2unicode: Simplify process_fooscript().
latex2unicode: Enhance stackautomaton() for delimiter strings.

Previously, stackautomaton() could only handle character-delimited
stacks, like '{foo}'.  Now things like '\left( foo \right)' are
possible.
L2U/Handlers.pm: Rewire handle_sqrt() for readability.

Readability of the resulting presentation, emphatically not the code.
L2U/Handlers.pm: Implement a handler for \left (finally!).

Together with \langle and \rangle, this is another milestone.
L2U/Handlers.pm: Modify handle_sum() and handle_int().

The dynamic size adaption just doesn't work out.
t/delims.t: Add new test category for delimiters.

With the new stackautomaton() and handle_left(), many previously
unheard-of things are now possible.
t/brightmare.t: Adapt tests for new sqrt_handler().
t/complex.t: Adapt tests for new handling.

New handle_sqrt, new fooscript handler and new integral/sum handling.
t/brightmare.t: Enable new tests (stacked fracs!)
t/celebrities.t: Adapt for new \sqrt and add new tests (sin/cos and Dirac delta).
t/complex.t: Add new, spectacular delimiter test.