implement GNU uniq(1) extension

[Takehiko NOZAKI]

T/O

[Takehiko NOZAKI]

done, see https://bitbucket.org/tnozaki/uniq

but Issue #105 is show stopper, our getopt_long(3) is broken and new uniq(1) use it.

[Takehiko NOZAKI]

done, see <<cset 4d704feba757>>

i changed long option's handling, so works with NetBSD's broken getopt_long(3).