Upgrade to Guava 16.0.1.
Merge pull request #29 from alfthomas/guava16

Upgrade to Guava 16.0.1
Bump git plugin
[maven-release-plugin] prepare release httpcache4j-4.0-RC4
[maven-release-plugin] prepare for next development iteration
Update README
Bump some versions
Remove deprecation warnings
setHeader
Normalize Accept headers

o sort Accept headers so we can be nice to servers and ourselves.
o Vary works with more types of preferences.

Fixes #31
[maven-release-plugin] prepare release httpcache4j-4.0
[maven-release-plugin] prepare for next development iteration
Updated version in README.md to 4.0