pulled the messages out for p_delete into a print method.  This makes the function body less verbose.  Added a `quiet` argument.  We talked about using `verbose` but quietly seems to be what library function uses and Yihui uses a quit parameter.  I like quiet but am open to what ever.  What ever we use we need to be consistent.  If Dason approves of the print method approach it should probably be used with other functions like `p_load`.

Reference issue #11