Fix documentation for mrbgems
Merge pull request #682 from bovi/doc-rake

Fix documentation for mrbgems
Add documentation for compilation process
Fix an unnecessary space
Merge pull request #683 from bovi/doc-compile

Add documentation for compilation process
Merge pull request #684 from bovi/tiny-beautify

Fix an unnecessary space
add mrb_mod_method_defined
add test for Module#method_defined?
Merge pull request #686 from skandhas/pr-add-Module-method_defined

Add Module#method_defined? for mruby
Merge branch 'master' of github.com:mruby/mruby