Add gconfig/xconfig support
Created by: steamp0rt
Hooray, I got gconfig to work! Also, kconfig_check and menuconfig have been merged into one command. Examples:
pmbootstrap kconfig check
pmbootstrap kconfig check --arch=armhf linux-postmarketos-mainline
pmbootstrap kconfig edit amazon-thor
pmbootstrap kconfig edit --frontend=g amazon-thor
pmbootstrap kconfig edit --frontend=ncurses amazon-thor
pmbootstrap kconfig edit --arch=armhf --frontend=gconfig postmarketos-qcom
closes #891 (closed) [x] Merge on GitHub (see https://postmarketos.org/merge)