Add some tests.
Add a comment. Kernel#require is defined in the mrbgem.
Add ARGV constant. It is not required by ISO. Compatibility with CRuby.
Fix a memory leak in mirb
Merge pull request #1161 from h2so5/fix-memory-leak-in-mirb

Fix a memory leak in mirb
Merge pull request #1157 from monaka/pr-add-ARGV-to-mirb

Add ARGV constant. It is not required by ISO. Compatibility with CRuby.
Merge pull request #1144 from monaka/pr-add-iso-conformance-tests-20130406

Add more ISO conformance tests.