Rayon library evaluation tracking issue

[alexcrichton]

• Comment "std-like" modules why they are the way they are
• Rename/move the iter::internal module
• Implement Clone for iterators where possible
• Move to concrete Send/Sync error type
• doc: Add crate-level documentation
• doc: Examples should use ? not try!
• doc: Documentation examples for parallel iterator methods
• doc: Modules should have documentation
• doc: Structures/types should all be documented
• doc: Missing attributes in Cargo.toml
• doc: Crate missing html_root_url attribute
• Configuration uses self instead of &mut self
• Configuration doesn't have a "build" method
• Public types should implement Debug
• Add an unsafe method to rayon-core to enable rayon-futures
• Consider adding a rayon-itertools crate
• Scope::spawn doesn't require Send
• rayon::spawn should document the lack of return value
• rayon::split available also at rayon::iter::split
• Bump rayon to 1.0

[nikomatsakis]

Going to close this since is duplicates the 1.0 milestone.