* change "pmbootstrap kconfig_check" to "pmbootstrap kconfig check"
* change "pmbootstrap menuconfig" to "pmbootstrap kconfig edit [-x|-g]"
(with legacy alias, because the first syntax was referenced to a lot)
* enable X11 interfaces: -x: xconfig, -g: gconfig
* new function to copy the xauthority file:
pmb.chroot.other.copy_xauthority()
* remove menufconfig() function from the kernel template and all kernel
aports ([skip ci] because it would rebuild all kernels and run out of
time). Alpine has dropped this as well, and it wouldn't work with the
new code anyway.
