Added an add_default_headers parameter to the make_request method. Added tests for it.
Added an option to turn off default response headers 'Server' and 'Date'. Also changed the code that processes the return from a handler, in order to support this new option. Added tests and docs.
Updated todo.txt.
Renamed todo.txt to TODO.
Added HISTORY file.
Merge branch 'dont-add-headers' into develop