add more explicit return type. s/private[scalaz] trait/private trait/
fix another stack overflow error when parse large CDATA
add test for #456
Merge pull request #464 from xuwei-k/xml-stack-overflow

fix another stack overflow error. add test for #456
Merge pull request #463 from xuwei-k/private-explicit-return-type

add more explicit return type. s/private[scalaz] trait/private trait/