Cake 2.4 behaviour callback compatibility fixes.
change method name
add alpha channel setting on creating thumbnail
add validation of php upload error
compatiblei to php5.4 more
…][$field.'_file_name'] is empty! so you better use !empty in this situation. it took me a really long time to figure out why the helper ignores the 'default_url' when the _file_name-field in the db is empty
Remove low() global function
…oved from CakePHP in v2.0. See http://book.cakephp.org/1.3/view/1134/low