Update history to reflect merge of #1063
Updated the docs for migrators so they're at least a bit more helpful.
Merge pull request #1136 from mojombo/migrators-docs-updates

Updated the docs for migrators
Update history to reflect merge of #1136
Fix syntax errors in Drupal migration docs.
Stick to the 1.0.x versions of rr
Convertible now reads an external metadata file (If available)
The metadata in the file itself is still read, and takes precedence.
Added Cucumber feature for external metadata.
Made it so files with external metadata are treated as Pages
Also, .metadata files are now filtered out of the outputted site.
Documentation now mentions external .metadata files
(Hopefully) fixed site.read_directories
Should pass test suite on Travis now. Or at least fail less.
Fixed typos in Cucumber features...
Convertible now reads an external metadata file (If available)
The metadata in the file itself is still read, and takes precedence.
Added Cucumber feature for external metadata.
Made it so files with external metadata are treated as Pages
Also, .metadata files are now filtered out of the outputted site.
Fixed typos in Cucumber features...
Refactor test in site.rb to be more readable
Fix bug with metadata merging.

If a Convertible instance already had metadata, the metadata on the file
itself wasn't being merged properly, because Array.merge was used
instead of Array.merge!
Merge branch 'external-metadata' of http://github.com/sequitur/jekyll into external-metadata