Update README.md

Fixed README.md for instructions on including recipe
Pass a unique digest to ruby_block within the update_file definition to prevent previous results of only_if/not_if being attributed to the current instance
added cron cookbook
[CC-675] Logrotate explicit about config permissions
Update env_vars README.md

Adds instructions for using environmental variables in a Rails console via the .bash_profile.
Update env_vars README.md

Adds instructions for using environmental variables in a Rails console via the .bash_profile and discusses alternative solutions.
Update env_vars README.md

Fixed spelling error.
Only install packages if not already installed.
Use enable_package to install memcached
Fix DJ script never killing child processes.
Improve compatibility with different Solr versions.
Upgrade Solr to version 4.9.0
Update Solr to version 4.10.0, utility instance named "solr4".
Compare Solr version numbers with Gem::Version
Update solr.xml template for Solr 4.
Merge pull request #1 from europeana/Europeana1914-1918-v3.1

Europeana 1914-1918 v3.1