Merge branch 'master' of https://github.com/mruby/mruby
Merge branch 'master' of https://github.com/mruby/mruby
should be flatten.
build gems if build_config.rb is modified.
note about $MRUBY_CONFIG.
Merge pull request #726 from mattn/fix_build_tasks

Fix build tasks
Merge pull request #727 from mattn/dep_gems

Add dependency to build gems list
Makefile: add all to test dependency
Merge branch 'master' of github.com:mruby/mruby
add new specifier "b" (boolean) for mrb_get_args()
eliminate unused array expression more aggresively
eliminate unused hash expression more aggresively
more aggressive code elimination for NODE_DOT{2,3}
fix typos
Doesn't clear black of all marked objects in major collections.
Since the minor collector doesn't need to mark these objects, the worst-case pause time is reduced.
Initialize edges of RRange.
Modify `Range#initialize` to accept optional `exclusive` argument.
change 2012 to 2013
Merge pull request #728 from takkaw/khash_typo

fix typos
Merge pull request #729 from authorNari/unclear-black-in-major-collector

Doesn't clear black of all marked objects in the major collector.