* Rebase and fix compilation errors (tests not yet fixed)
* Use `debug_assert` over `assert`
* Fix tests
* Assert safety, clean up
* Fix up stale cache removal, move one assert to debug_assert
* Remove printlns
* Add licenses
* Fix benches
* Inline some no-ops in a hot loop that weren't being inlined
* Add spooky comment to make sure no-one removes the inlining annotations
* Minor cleanup
* Add option to switch between mmap and ram
* Flag ethash to use less memory when running light client
* Fix tests
* Remove todo comment (it's done)
* Replace assertion with error return
* Fix indentation
* Use union instead of `transmute`
* Fix benches
* Extract to constants
* Clean up and fix soundness holes
* Fix formatting
* Ignore missing-file errors
* Make incorrect cache size an error condition instead of a panic, remove dead code
* Fix compilation errors from rebase
* Fix compilation errors in tests
* Fix compilation errors in tests
