add mrbgem: mrb-array-ext
update build_config.rb
rename method
Remove bit-fields. They doesn't reduce memory on major environments.
Merge pull request #1009 from skandhas/pr-add-mrb-array-ext

add mrbgem: mruby-array-ext
obsolete mrb_object; opposite of bc870ce
rename mrb_basic to mrb_basic_ptr; close #1011
removed compatibility macros mrb_ary_new_elts() and mrb_ary_new4()
Merge pull request #1010 from monaka/pr-remove-meaningless-bitfields-in-irep

Remove bit-fields. They doesn't reduce memory on major environments.
fix segmentation fault in BasicObject#inspect
Merge pull request #1013 from takkaw/fix_bo_missing

fix segmentation fault in BasicObject#inspect