2017-04-12

Added

• fallible setters, e.g. #[builder(try_setter)]. These setters are exposed
  alongside the normal field setters and allow callers to pass in values which
  have fallible conversions to the needed type through TryInto. This
  attribute can only be used on nightly when #![feature(try_from)] is
  declared in the consuming crate's root; this will change when Rust issue
  #33417 is resolved.