Generalized efficient manipulations of sequences of primitive datatype.  Includes
specializations for java arrays and nio buffers.  There are specializations to allow
implementations to provide efficient full typed copy functions when the types can be
ascertained.  Usually this involves a double-dispatch on both the src and dest
arguments:

https://en.wikipedia.org/wiki/Double_dispatch.

Generic operations include:
1. datatype of this sequence.
2. Writing to, reading from.
3. Construction.
4. Efficient mutable copy from one sequence to another.

Datatype library primitives shared between clojurescript and clojure.  The datatype
system is an extensible system to provide understanding of and access to an undefined
set of datatypes and containers that hold contiguous sections of those datatypes.

Java specific mappings of the datatype system.

1.  Generalized support for datatypes not present as jvm primitive types but which
can be store on a 1-to-1 correspondance with a jvm primitive type (so things that
need 1,2,4, or 8 bytes to store per element).
2.  Unsigned integer support for nio buffers.