Do not overwrite container volumes from config

Fixes #819 Use same persistent volume when a container is restarted
Bump version to 0.5.0
Testing, issue #1217: Add coverage testing into docker-ci
Small changes in changelog wording
Changed date on changelog
Make dockerfile docs easier to find. Clean up formatting.
Add unit tests for buildfile config instructions

Add tests for instructions in the buildfile that
modify the config of the resulting image.
Merge pull request #1169 from crosbymichael/buildfile-tests

Add unit tests for buildfile config instructions
change -b -> -v and add udp example
Merge pull request #1226 from metalivedev/easydockerfile

Make dockerfile docs easier to find. Clean up formatting.
Merge pull request #1227 from dotcloud/bump_0.5.0

Bump to 0.5.0
switch version to -dev
Merge pull request #1230 from dotcloud/switch_dev

switch version to -dev
Merge pull request #1232 from dotcloud/1217-testing-coverage

Testing, issue #1217: Add coverage testing into docker-ci
Merge pull request #1207 from crosbymichael/819-use-persistent-volume

* Runtime: Do not overwrite container volumes from config