Change the DebugInterface, PPCDebugInterface, and DSPDebugInterface to use CamelCase names.

This is the standard coding convention in the codebase, so our interfaces should use it too.
Merge pull request #128 from lioncash/normalize-debug-interface-func-names

Change the DebugInterface, PPCDebugInterface, and DSPDebugInterface to use CamelCase function names.