Profiler and a bit of tuning

See

* http://www.ohmyenter.com/?p=70

    - Used `rack-mini-profiler` and tuned the top page a bit based on it. 

* http://www.ohmyenter.com/?p=105

    - xxx_path was not so slow, I did not change. 
    - I don't know about slim's render is slow, or not

- http://www.ohmyenter.com/?p=128

    - I did not tune up the javascript codes, yet.