#83, refactor the database code to make it possible to add in the equivalent pieces
#83, add equivalentValue to the Rule typeclass
#83, rename FileTime to FileInfo, since I'm going to make it also return the file size
Make noTest build at -j3, try and make :test go a little faster
Switch to copyDirectoryChanged, give some scope for future tests going faster if things suit it
#83, rename FileTime to ModTime
Make getModTime become getFileInfo and return the size at the same time