JITX circuit debugging utilities

Provides the following packages:

• debug/test-points : Automatically generate and customize test-points for your board
• debug/header : A generic module for connecting 10-pin debug header components to a JITX design.
• debug/tag-connect/... : JITX implementations of tag-connect header components.
• debug/samtec/... : JITX implementations of samtec header components.