return self in option method to support chaining

Lets us do something like $('#timepicker-input').timepicker('option', 'option1', val).timepicker('option', 'option2', val).show();
Removed duplicate wrapping of 'this'

For the methods option, getSecondsFromMidnight, getTime, setTime, and remove, 'this' is already a jQuery object, so $(this) in those methods is actually $($(this)).
See http://docs.jquery.com/Plugins/Authoring#Context
Updated version number and minified library.