* Fixed type of `matrix-expt'
* Made matrix functions respect `array-strictness' parameter (mostly
wrapping functions with `parameterize' and return values with
`array-default-strictness'; reindentation makes changes look larger)
* Added strictness tests
(cherry picked from commit f40ad2ca9d)
* Gram-Schmidt using vector type
* QR decomposition
* Operator 1-norm and maximum norm; stub for 2-norm and angle between
subspaces (`matrix-basis-angle')
* `matrix-absolute-error' and `matrix-relative-error'; also predicates
based on them, such as `matrix-identity?'
* Lots of shuffling code about
* Types that can have contracts, and an exhaustive test to make sure
every value exported by `math/matrix' has a contract when used in
untyped code
* Some more tests (still needs some)
