Add cryptopp subproject.
Removed cookie handling from request and response classes.
Removed misleading comment and unused variable.
Added repeatable header support to response (for cookies).
Added raw header support for request (for cookies).
Added template parameters RequestT and ResponseT, for easy mocking during tests.
Created internal_error exception - HTTP error with code 500
Convert to new cookie processing method
Convert to new context instanation method; Silence compiler warning about unused argument
Use named exception instead of http_error(400)
Created cookie_context class, for handling HTTP cookies
Created encrypted cookie context, for handling secure, not tamperable and authenticated cookies.
Tests for webpp routing and controller method execution
Added tests & new headers to cmake