Merge pull request #243 from YungSang/topic

Needs 'X-tumblr-puppies' header to post
Implement CommandQueue
Add console.error to investigate cause of the error
Use CommandQueue to queue posting to Tumblr
Test command_queue.js by JSHint
version 3.0.8-dev starts
Serialize command execution on CommandQueue
version 3.0.9-dev starts
version 3.0.10-dev starts
Fix a bug on Tumblr IDs which have the main blog ID as a prefix