small cosmetic variable renaming
small refactoring (dedup mrb_vm_cv_set)
Merge branch 'master' of github.com:mruby/mruby
Add mruby-string-utf8
Merge branch 'mruby-string-utf8' of https://github.com/mattn/mruby into mattn-mruby-string-utf8
mruby-string-utf8: UTF-8 string may contail NUL; #1646
mruby-string-utf8: redefine String#size for UTF-8 string; #1646
Remove duplicate test
Merge pull request #1647 from mattn/remove_duplicate_test_for_mruby_string_utf8

Remove duplicate test for mruby-string-utf8
dump.c: wrong filename table dump for multiple script files; close #1648
Merge branch 'master' of github.com:mruby/mruby
skip "trace:" header if no backtrace line exists
Merge branch 'master' into iij