Fix a bug in Node.js environment
Expose setTimeout
Add specs for callback order
Add seajs.require method
Add test specs for seajs.require method
Rebuild packages
Emit error event on null exports
Add specs for error event
Improve specs for error event
Change version to 2.0.0
Improve docs
Rebuild packages for 2.0.0
Improve docs
Merge branch 'master' into gh-pages