ENH: make ITstream positioning methods noexcept

ENH: add rank() method for compound tokens

ENH: add IOstream::minPrecision(unsigned)

- reduced typing, more expressive, no namespace ambiguity with max()

    new: IOstream::minPrecision(10);
    old: IOstream::defaultPrecision(max(10u, IOstream::defaultPrecision()));

STYLE: namespace qualify min/max for some buffer sizing [clang/hipp]