Only ignore indexes after first nonzero, preserving pregaps but
appending them to the previous track instead of prepending to the
current. The first index of the first track is used for the start time
regardless of its number. Unneeded bool last_updated removed.

Apparently all other C libraries are not compatible with "constexpr".
Those which are not will get a performance penalty, but at least they
work at all.

Use the first INDEX in each TRACK section, instead of the last, for the
start time. This preserves the original CD layout (including gaps
between tracks), and avoids skipping sections of songs in more exotic
cuesheets (eg musical suite tracks).

Fixes 0004355 and 0003359

Wrapper for protocol/ArgParser.cxx.

Using unsigned(-1) renders undefined behavior.