Add BusyBird::Main::PSGI::View. Write POD about it (in progress...)
Config.pod: minor fix for the POD.
Main::PSGI::View: complete its public spec along with test script t/Main_PSGI_View.t
Implement Main::PSGI::View by move code from Main::PSGI. Pass the tests.
Main::PSGI::View: write POD about template_functions.