Include stddef.h. It is required by size_t. In case you include stdio.h, stddef.h is included indirectly.
Separate FILE dependencies with ENABLE_STDIO.
Reduce using snprintf(). They can replace by mruby API.
Add stdio.h. This is just for now. We should discuss about remote tests later.
Make topenv() static inlined
Merge pull request #1066 from xxuejie/static_inline_top_env

Make topenv() static inlined to avoid compiling error when using clang and -O0 mode
Fix indentation in mirb.c
mruby-sprintf should precede mruby-print
Merge pull request #1070 from mattn/fix_order

mruby-sprintf should precede mruby-print
Merge pull request #1069 from kano4/pr-fix-indentation-in-mirb_c

Fix indentation in mirb.c
Merge pull request #1065 from monaka/pr-reduce-stdio-dependency

Reduce stdio dependency
remove unused functions 'mrb_strerrno' and 'mrb_bug_errno'.
Merge pull request #1071 from crimsonwoods/remove_strerror

remove unused functions 'mrb_strerrno' and 'mrb_bug_errno'.