disable checking ID when loading models (fix #679)
eliminated ::log ::exp ::sin ::cos ::pow ::ceil ::sqrt
add cmath_finder.sh which greps whole source tree
util::vector's abs is member function
abs for user-defined type should not be std::abs
Merge pull request #689 from jubatus/feature/eliminate_cmath

Eliminate cmath
Merge pull request #687 from jubatus/fix-679

disable checking ID when loading models (fix #679)