Refactor MySQL bindings and client packages.

The current MySQL module is hard to modify, test, and drop in
replacement components to.  This work starts out by refactoring
the bindings support in MySQL to a completely seperate bindings
class in order to reduce the amount of parameters in the main
class for a feature that is infrequently used.

In addition to this start the movement of client configuration
and packages to the mysql::client::* namespace.
Merge pull request #232 from apenney/refactor-round-1

Refactor MySQL bindings and client packages.