make round be round-ties-even, miscellaneous changes to the rounding procedures - #530

Bad response: 500 {"message":"Build processing error.","error":true,"url":""}

unused import: `Color`

unused import: `SerializableSteelVal`

unused import: `abi_stable::std_types::RBoxError`

unused import: `std::rc::Rc`

`steel-async-webrequests` (lib test) generated 1 warning

`steel-interpreter` (example "spellcheck") generated 1 warning

struct `AsyncResponse` is never constructed

unused import: `ShareableMut`

field `0` is never read

struct `BlockingResponse` is never constructed

The `set-output` command is deprecated and will be disabled soon. Please upgrade to using Environment Files. For more information see: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/

The `set-output` command is deprecated and will be disabled soon. Please upgrade to using Environment Files. For more information see: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/

The `set-output` command is deprecated and will be disabled soon. Please upgrade to using Environment Files. For more information see: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/