+'UploadVerifyUpload': Upload verification, based on both file properties like
+MIME type (same as UploadVerifyFile) and the information entered by the user
+(upload comment, file page contents etc.).
+$upload: (object) An instance of UploadBase, with all info about the upload
+$user: (object) An instance of User, the user uploading this file
+$props: (array) File properties, as returned by FSFile::getPropsFromPath()
+$comment: (string) Upload log comment (also used as edit summary)
+$pageText: (string) File description page text (only used for new uploads)
+&$error: output: If the file upload should be prevented, set this to the reason
+ in the form of array( messagename, param1, param2, ... ) or a MessageSpecifier
+ instance (you might want to use ApiMessage to provide machine-readable details
+ for the API).
+