Allow user to upload image.
Add User Avatar.
Modify git ignore.
Upgrade the bootstrap-dropdown to fix the conflict with jcrop.
Optimize the code and modify the view.
Fix the code bad smells.
Fix the small bugs.
Merge pull request #19 from jameszhan/dynamic-widget

Dynamic widget
fix login user bug.
add contributor image and add user default_avatar
add contributor image and add user default_avatar