mattdrayer/rebase-20140916: Initial test fixes

@antoviaque -- some updates to address various failing unit tests in the rebase branch.  I'm still observing two test failures on my local machine, but I'm not sure how to address them at the moment or if they are even a problem outside of my workstation -- so maybe we can discuss those and submit a follow-on PR if necessary.
I'd prefer more investigation before merging this code, which breaks several abstraction barriers. One potential issue could be that `FieldDataCache` isn't actually a read-through cache. It expects you to pre-load it, and if you haven't done that correctly, then you might see this issue. A better fix might be to make it act as a proper read-through cache. That would make it so that the code would be more consistently correct (although failing to pre-load the data would still make for a performance hit).