Remove empty lines.
Fix allocation-error-handlings for scope_new().
Add API `mrb_data_init` to initialize `MRB_TT_DATA` tagged instance.
Merge pull request #2546 from cubicdaiya/issues/emptylines

Remove empty lines.
should use non NULL scope for raise_error(); ref #2547
Merge branch 'cubicdaiya-issues/scope_new_error_handlings'
Merge branch 'master' of github.com:mruby/mruby
Merge pull request #2548 from take-cheeze/mrb_data_init

Add API `mrb_data_init` to initialize `MRB_TT_DATA` tagged instance.