added isHeaderSent options
fixed typo
moved get & set header to response widget
fixed test resposne not in unitTest mode
fixed test resposne not in unitTest mode
added unit test detect for setcookie
improved coverage for response widget
returns bool return for sendHeader
keep cookies after sent`
detect whether logger is exists when header has been sent
updated response widget docblock
updated cookie and header widget class description
Merge pull request #117 from twinh/refactoring/response

Refactoring response widget, close #116