Make error handler check whether Bundler is used
Improve check for Bundler+Gemfile presence
Fix expectation for LoadError test case
Add #load_site method to command runner (a complement to #require_site)
Make #require_site and #load_site public
Update old nanoc.stoneship.org references
Update old references release note entry in NEWS
Remove unused debug statements
Fix and improve #resolution_for with Bundler test
Fix Pruner not deleting nested empty dirs
Add test case for pruning nested empty dirs
Use Array instead of Set in Pruner to ensure order preservance
Merge pull request #218 from reima/release-3.5.x

Fix Pruner not deleting nested empty dirs
Merge branch 'release-3.5.x'