scripts/image: simplyfing detection of devel version, thanks to '_gio'

Signed-off-by: Stephan Raue <stephan@openelec.tv>
new package: add package 'arm-mem' and 'arm-mem-initramfs'

Signed-off-by: Stephan Raue <stephan@openelec.tv>
eglibc/eglibc-initramfs: replace package 'libcofi' with package 'arm-mem'

Signed-off-by: Stephan Raue <stephan@openelec.tv>
remove package 'libcofi' and 'libcofi-initramfs'

Signed-off-by: Stephan Raue <stephan@openelec.tv>
tools/mkpkg: add script to get and pack package 'arm-mem'

Signed-off-by: Stephan Raue <stephan@openelec.tv>