mruby/mruby — pull request #2142 by cremno (2014-04-27 20:50:35+00:00)
Title: rename `mrb_str_buf_append` to `mrb_str_cat_str`

I think the new name is better and less confusing, because:
- `mrb_str_append` calls `mrb_str_to_str` and this function doesn't
- `mrb_str_buf_append` __is__ `mrb_str_cat` for `mrb_value` strings