Release_1.7.0

Update readme to include the unxz and wrap work

Fix checksums.

Update submodules

update other architectures to reflect the updated unxz sources

Update unxz to correctly handle compressed/uncompressed sizes

This is needed for extracting linux-4.14.336.tar.xz

Update to include unxz in the final package set

Update bootstrap seeds.

Bump version number to 1.6.0 in changelog.

Update submodules.

Update mescc-tools-extra.

Update M2-Planet.

Update bootstrap seeds submodule (only comment updates).

Update answer checksums

Update mescc-tools to support more command line arguments in kaem.

Mention M1 in ChangeLog entry.

Fix another typo in changelog.

Fix a typo.

Update mescc-tools.

Update submodules to pull in lowercase riscv defines and some fixes to M1.