Adds the `pckernel` system to Jak 2, allowing you to do the PC-specific
things that Jak 1 lets you do like change game resolution, etc.
In other to reduce the amount of code duplication for something that
we're gonna be changing a lot over time, I split it into a few more code
files. In this new system, `pckernel-h.gc`, `pckernel-common.gc`
(previously `pckernel.gc`) and `pc-debug-common.gc` are the files that
should be shared across all games (I hacked the Jak 2 project to pull
these files from the Jak 1 folder), while `pckernel-impl.gc`,
`pckernel.gc` and `pc-debug-methods.gc` are their respective
game-specific counterparts that should be loaded after. I'm not fully
happy with this, I think it's slightly messy, but it cleanly separates
code that should be game-specific and not accidentally copied around and
code that should be the same for all games anyway.
