Implemented Single threaded Dispatcher,wrote test cases

I've implemented single thread dispatcher. If this is correct then I'll update it to concurrent version which I've started. I just wanted to confirm my approach.
In your configuration structure, it might make sense to define support for a wildcard mapping as a catch all default.
In most applications, the static file handler is generally the wildcard. If no handlers are found, then a static file handler is used. Might save you on the configuration.