v1.7.6 release

Bug fixes :

• Fix cache issue in resize.blade.php and crop.blade.php.
• Fix resizing and cropping on Windows.
• Fix issues of creating default folders.
• Fix routing of non-public files.
• Refactor grid view and list view. Related css and js files are also refactored.
• Sort folders by names in tree view.

Features :

• Default lfm type will be "file" if request parameter type is not specified.
• Display original image when thumbnail is missing.