Add support for locale-specific size indications (e.g.,

Add support for locale-specific size indications (e.g.,
thousands-separators) and for explicit size suffixes on output.

(Block size): Say that:
This affects display format as well as block size.
Fractional block counts are rounded up.
ls file size blocksize defaults to 1.
A block size spec preceded by ' generates thousands separators.
A suffix without a preceding integer generates suffixes.
(tail invocation): 32k -> 32 KiB.
(What information is listed): ls -h is now equivalent to
ls --block-size=human, and ls -H is now equivalent to
ls --block-size=si.  Displayed file size is now always affected by
--block-size.