fix typos in sample code, add enum to json encoder, add test case
json bugfixes
tidy
json bugfix
json add enum encoder test case
re-special-case Option in JSON encoding
json tidy
added issue for reference in FIXME
added rather elaborate test framework
Partially de-vec-mut librustc
RIMOV core::run
RIMOV core::rand
RIMOV core::io
RIMOV core::hash
RIMOV core::vec

Also remove as many uses as possible of vec::cast_to_mut and
cast_from_mut
retabbing
core: add min and max to cmp, re-export various places.
core: add abs to num.
std: add stats.
rustc and std: teach about #[bench], modernize to use quote_expr! some.