bolero-MURAKAMI/Sprout — pull request #66 by kariya-mitsuru (2014-07-15 16:25:57+00:00)
Title: fix math::is_odd for a negative argument

I think that sprout::math::is_odd(-1) should be true.

It also fixes math::pow for a case that x is a negative and y is a negative odd integer.

cf. http://melpon.org/wandbox/permlink/XVKea2I6CdVJCbZX