get it running on 1.9
backport caching nil and only caching with symbols
do not blow up on nil ids
support find_feature
2.4 strain for carzy monkey patches
fix tests
fix caching of find_feature
ignore gemfiles for clean branch switches
avoid 1 query when we already fetch everything
downgrade rubygems on travis
Merge pull request #59 from grosser/deprecated

update rails 2 branch