Add support for inserting raw headers
Fix up insert_raw so that it compiles.
Merge branch 'header-insert' (#88).
Rust update: ~str and tm_zone in time::Tm are gone
Rust update: StrBuf -> String
Rust update: `extern crate debug` and more deprecated `to_lower` and `to_upper`
Merge pull request #89 from Ogeon/master

Rust update: ~str and tm_zone in time::Tm are gone and some more
Add a note about the obsoletion of this project.
Upstream: Eq/Ord → PartialEq/PartialOrd.
gitgnore doc/{*.woff,implementors/}.
Support both python3 and python2 for comparisons.

Also add tests for concurrency levels 16 and 32, now that I have a
laptop with four cores and eight threads rather than just two cores.
Upstream: TotalEq → Eq.