respect the Accept header's value and provide the way to supply de/serialier subroutines.
- modularised the codebase, so that code for executing each default http method for a resultset is now in separate method.
- allow for overriding methods for particular resultsets or globally.
Also respect individual implementations for the rest methods in the resultset classes.
added tests.
updated dependencies.
fixes.
now passing the tests.
basic docs skeleton, version.