cmd1.bbclass: Ensure ncurses is built and used for menuconfig tasks

cmd1.bbclass: Ensure ncurses is built and used for menuconfig tasks

Currently, the task just exits if something goes wrong. This adds the
ncurses-native dependency. It also adds a small delay before closing the
window so any messages displayed there can be seen.

Trying to get the kernel build system to correctly find and link with
our copy of ncurses is some kind of nightmare. I ended up having to add
it to HOST_LOADLIBES globally for this task which is rather nasty but I
couldn't find any other way.

[YOCTO #2513]

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>