fix defined typecheck
Add VM switching API.
fix JSmodlue
add Json.new(Class)
Merge pull request #381 from tetsurom/SwitchVM

this is an API for using built-in virtual machine
add dummy library: Lib.Document
fix jsmodule
Merge pull request #362 from imasahiro/fix_defined_typechecker

Fix 'defined' syntax's typechecker
move kNode's node to magicflag
Merge pull request #380 from konoha-project/fix_stackbase

Move kNode's node to magicflag
add bug script (NUL character cause infinite loop)
Merge pull request #383 from wakamori/add_bugscript

add bug script (NUL character cause infinite loop)