initramfs/newroot: add tmpdir module

Precreates NEWROOT/tmp and per-user directories in NEWROOT/tmp/users.
Also added newroot_setup_tmpdir() to the setup module.
liram/util: liram_unpack_etc()

Replaces or simply unpacks etc, depending on LIRAM_ETC_INCREMENTAL.
liram: misc update

* core: export tmpdir / etc unpack functions
* layout/README: minor addition
* layout/default: use etc unpack function
liram/layout: add 'tv' layout

A rather strict layout, see its header comment for details.
lib/fs/dodir_minimal: fix dodir_minimal()

Typo fix, ']' was missing.
scripts/devel/kcomp: fix typo

That thing is called K-E-R-N-E-L, not K-E-N-R-E-L.
lib/test/assert_common: assert function_defined
newroot_setup_mountpoints: use default file

The function comment claims that newroot_setup_mountpoints() will use the
default config file if called without args, but the respective code was
missing in its body. This commit fixes that.
initramfs/misc: bypass qwhich check

Calling "qwhich rsync" in initramfs_copy_file() seems to be broken.
Using hardcoded rsync path for now.