fixed #383
bugfix: gravatar images dosen't appear properly at code browser

- fix at commit history view
- fix at code browser file list
Merge pull request #385 from wansoon/issue-bugs

마일스톤뷰에서의 이슈 대량업데이트 오류수정
css-style: rendered README & project menu

- increase README body font size
- increase padding project menu items
code: Fix the binary detection for file's contents

* Server does
    * Decide whether the file is binary or not.
    * Decide the file's mimetype using Tika.
    * If the file is larger than MAX_FILE_SIZE_CAN_BE_VIEWED, does not
      send its contents.
* Then client does
    * If the contents is empty but the size is larger than zero, client
      treat it as a binary file so show a link to downloda the file.
    * If the file is not binary, client show the file as image if the
      mimetype matches with "image/*" else show a link to download the
      file.
    * If the file is binary, client show the file as source code and
      apply syntax highlight by its language. The language is often
      specified by the server in the subtype of the mimetype; If not the
      client decides it by the file's extension.