Fixes for MSL (#580)

* Some potential fixes for MSL

Post-conflict fixes

More conflict merging

More reconciliation with recent ale

More reconciliation

Fix for pixel size

* Bugfix for focal length lookup for nav cam

* Make some MSL tests pass

Undo some tests

* Fix for nadir mode with MSL cameras

* Spellcheck

* Add changelog note for MSL

* CHANGELOG: Spell

* Move changelog note