Send Resource via router!

Users can now send resources via the sendResource method!

More Updates: See notes

Fixes #2

Freezes various objects where applicable.
Switches from plain js objects to Map where applicable, for better memory performance/gc.
Starts the process of setting up body parsers for various content types.
Handles issue of returning response correctly.
Brings in the x.d.ts file from moddablejs
Adds better manifest support from issue #2 , so it's more inline with other modules.

Initial Release

Works for get routes responding with a status and a json body. Super young. Use at own risk.