Extract diffing code to support.
Merge pull request #441 from phiggins/extract-differ-to-support

Extract differ to support
Fix docs.

[ci skip]
Don't blow up when generating a failure message involving stdout/stderr.
color_enabled is going away, replace with color
Merge pull request #509 from rspec/remove_color_enabled

color_enabled is going away, replace with color
Fix `change` matcher to work properly with `IO` objects.
Don't raise errors in exists matcher

Fail gracefully instead
Merge pull request #508 from rspec/fix-io-error

Don't blow up when generating a failure message involving stdout/stderr.
Merge pull request #511 from danielfone/composable-exists-matcher

Don't raise errors in exists matcher
Add a changelog entry for #511.
Improve wording a bit.
Updated travis build scripts (from rspec-dev)
Merge pull request #512 from rspec/update-travis-build-scripts-2014-03-29-for-master

Updates from rspec-dev (2014-03-29)
Merge branch 'master' of github.com:rspec/rspec-expectations into add_negation_matcher