add compatibility macro mrb_class_new_instance()
implement Class.new in C again
redesign mruby/data.h API; use DATA_PTR() for raw data pointer, DATA_GET_PTR() to type safe retrieval (TypeError will be raised), DATA_CHECK_GET_PTR() to get nil if type mismatched
remove alloc from Time class
remove Ruby defined Class#new
use newer DATA API
Fix return block argument error
Merge pull request #1475 from carsonmcdonald/fixparseerror

Return when block argument error