pass board dir to scripts instead of board name

[mck1117]

Allows for building boards that may not necessarily be in the config/boards directory. For example if you want to try rusEFI with some board but not merge yet, you can make a repo, submodule rusEFI, then put your board config files in your repo, then build without needing to modify rusEFI.

• Simplifies build scripts
• Simplifies java (java doesn't need hardcoded config/boards any more)
• Simplifies makefiles (same idea, future change to avoid duplicate lines in many board.h files)

I guess related to #5016

also fix #5033 the right way

[mck1117]

let's let #5018 go first

[rusefillc]

@mck1117 we now have #5018

[mck1117]

needs #5035