Update Debian

There are a few updates to packages in squeeze-lts, but see also https://github.com/tianon/docker-brew-debian/issues/12.
Bump jruby dev
Remove /root/.cpanm cache directory
Merge pull request #297 from tianon/debian

Update Debian
New registry version

Added the latest (0.9) - 0.8 will receive active support for the time being, but older versions are not to receive any specific attention and users should really migrate to one of the two latest releases.
Merge pull request #298 from cpuguy83/bump_dev

Bump jruby dev
Merge pull request #299 from PeterMartini/master

Remove /root/.cpanm cache directory
Merge pull request #300 from dmp42/patch-2

New registry version
Update docker-dev for consistency with other repos

This updates us to 1.3.1 and updates the tag format to bare version numbers instead of having the "v" prefix.
Update docker-library images

- `node`: NPM 2.1.7
- `php`: cut image sizes roughly in half across the board (docker-library/php#36)
- `redis`: drop official support for versions upstream doesn't support (docker-library/redis#15)
- `wordpress`: fix `chown` issue (docker-library/wordpress#21)
CRUX: Updates to 3.0 and 3.1 packages
Merge pull request #306 from therealprologic/master

CRUX: Updates to 3.0 and 3.1 packages
Merge pull request #302 from infosiftr/update-docker-library

Update docker-library images
Update docker-library

- `python`: remove source and skip tests (docker-library/python#20)
- `tomcat`: 8.0.15
Add r-base, an official container for R

The r-base image is maintained by the [rocker-org](https://github.com/rocker-org/rocker) project. This would add support for an official container for R, as suggested in https://github.com/rocker-org/rocker/issues/16
Merge pull request #308 from infosiftr/update-docker-library

Update docker-library
list both maintainers
fix git url (use `://` not `@`)
Merge pull request #304 from tianon/update-docker-dev-for-consistency

Update docker-dev for consistency with other repos
Update docker-library

- `php`: fix some Apache woes (docker-library/php#43), and add `docker-php-ext-install` and `docker-php-ext-configure` (docker-library/php#41)
- `tomcat`: 7.0.57
- `wordpress`: push more of the PHP+Apache logic into `php` where it belongs (docker-library/wordpress#25), and update the image to use the new `docker-php-ext-install` magic for the extra core extensions it needs (docker-library/wordpress#26)