added spec for full weight
fixed method call
added full_weight method
fixed typo
added full gravity method
added spec for files
added #videos method
added spec for documents
added spec for text files
added #text_files method for file parser
added spec for song types
added #songs for file parser
added spec for #unknown_formats
added .bin as a constant
added method for unknown formats
added spec for added weights and gravities
declared parser as instance variable
added added gravity and weight to the view
replaced word weight with size for better semantics
changed weight for size