Code should be updated for modern versions of nxdk

[JayFoxRox]

nxdk had a lot of changes since this was originally made:

• "stdio.h" should be included as <stdio.h>.
• <xboxrt/debug.h> moved to <hal/debug.h>.
• Windows Sleep should be used instead of XSleep.
• For exit, just return from main.
• Wildcards in makefile are discouraged.
• pbkit is not necessary for just using debugPrint (not a change in nxdk, but in how we recommend it)
• NXDK_DIR should already be set when the Makefile is started, to allow compilation out-of-tree. (not a change in nxdk yet, but a good rule in general)

Recompiling will also improve the font (soon, see upstream nxdk PRs) and include fixes to video-modes (which otherwise prevent nxdk applications from working with some EEPROM and cable configurations).