serialize: Remove errant println!'s from decode
shootout-fannkuch-redux rewrite

Less bound checking and parallelisation.  Brute speed improvement
is about 15% faster.
Fix spelling mistakes in documentation and code.
auto merge of #13633 : TeXitoi/rust/shootout-fannkuch-redux-rewrite, r=alexcrichton

Less bound checking and parallelisation.  Brute speed improvement
is about 15% faster.

The unsafe block improve the brute speed by about 5%.
auto merge of #13635 : richo/rust/no-output-from-serialize, r=sfackler

As an aside, it seems like a lint for libraries calling println! might be a useful thing?
auto merge of #13640 : jbcrail/rust/spelling-updates, r=alexcrichton