Change to use assert method.
Fix to not print unnecessary comma.

When `n2->car` is 0 and `n2->cdd` is not 0,
unnecessary comma was printed before first local variables.
Unsupported Regex in mrb_str_aref_m()
Proc class define before a first method

mrb_define_method setting mrb->proc_class for method proc
arity for cfunc is not implemented yet
remove superclass test for classes that do not exist in mruby (core)
update String#slice doc
Merge branch 'suzukaze-delete-string.slice_comment'
Merge branch 'master' of github.com:mruby/mruby
resolve conflict
git push origin masterMerge branch 'yui-knk-replace-assert'
fix conflict resolution mistake
Modify return value of String#slice! if idx == self.size
Merge pull request #2406 from iij/pr_string_slice_bang

Adapt a behavior of String#slice! to other Ruby implementations
Add notes about how to use mrbconf.
Add primitive type configuration document.
Document GC mrbconfs.
Merge pull request #2407 from take-cheeze/mrbconf_update

Update mrbconf document.
clear local variables for the first execution of mrb_context_run(); close #2405
Syntax highlight code blocks with github flavored markdown.