Generalized the Converter interface to convert from classes
other than just String. Modified implementations accordingly.

Threshing out an alternative approach to the DSL that is more
consistent between parser implementations, more complete,
and does not involve static imports.
Fixing up some issues - still getting used to intellij which
doesn't constantly recompile the entire project on the fly...
refactoring towards a single consistent dsl for xml parsing, and likewise for json parsing
much improved json parsing dsl
Working through some more modifications to the json parsing dsl, including setting up converters as part of the definition of the document
fixed a silly bug in StringConverter
wrangling generics to support type-safe converter-registration method chaining