Revert "ZSH prompt: use bold black instead of "faint" normal, because "faint" isn't widely supported"

This reverts commit 78b421e4a9e7e6af3bdc0b804d526b77243ca045.
Revert "Changed git colors so they don't depend on "bold reverse" creating a bold background"

This reverts commit aeffee0549f58487c3dbe2bb835690697d20759f.