Build Travis CI builds with `sudo: false` and `travis-cargo`.
 Update the `$PATH` env var in `before_install` of `.travis.yml` to include the
 directory containing the rust tool chain binaries.
 Modify `.travis.yml` to install freetype via homebrew on OS X for Travis CI
 builds.
 Add `travis-cargo` to perform a build, test, and bench with the proper features
 on all of the build trains.
 Enable `travis-cargo` doc upload for stable builds on the master branch.
 Add code coverage checking via coveralls.
 Add the `RUST_BACKTRACE=1` env var for builds.
 Add the `TRAVIS_CARGO_NIGHTLY_FEATURE` env var to specify the default feature
 for nightly builds.
 Add secure `GH_TOKEN` for doc uploads.
 Restrict Travis CI builds to `master` and `auto` branches, as well as PRs.
 Allow build failures on rustc nightly.
 Enable `fast_finish` for the build matrix.
 Add japaric/rust-everywhere scripts to `ci` directory.
 Use rust-everywhere scripts in Travis CI.
 Use `cache: cargo` to cache cargo builds.
 Add `PROJECT_NAME` env var to define the project name for rust-everywhere
 releases.
 Configure the build matrix to build across stable, beta, and nightly.
 Configure the build matrix to build on OS X and linux.
 Configure the build matrix to build on i686 and x86_64 for linux.
 Add `before_deploy` and `deploy` sections to `.travis.yml` to configure
 deployment of build artifacts for all matrix targets when a new tag is pushed.
 Enable builds on tag branches using a Ruby regex.
 Configure notifications to be disabled for successful builds.

Update badge layout.
Add "API Docs" badge to link the crate documentation.
Add "Crates.io" badge to link to the latest crate version on crates.io.
Add "Coverage Status" badge to display the current test coverage status via
coveralls.io.
Update the project summary.
Add a table of contents.
Add a section on precompiled binaries.
Update the section on building and compiling from source.