lib/initramfs: fixup

* newroot/setup: fix tmpdir creation
* newroot/liram/layout/tv: call newroot_setup_premount() before dirs,...
* cmdline/parser/liram: accept novdr opt which sets LIRAM_LAYOUT_TV_WITH_VDR=n
scripts/shlib-call-minimal: fix error message
scripts/liram/pack_tv: detect WITH_VDR_TARBALLS

Also: exclude /usr/src