Updated Model dirty checks to ignore numerically equivalent fields
Fixed typos
Fix some comments.
Return 0 from sum if result is null.
Merge branch 'pull-request/ignore-numerically-equivalent-dirty-fields' of https://github.com/JamShady/framework into JamShady-pull-request/ignore-numerically-equivalent-dirty-fields
Clean up code. Method extraction.
Updated the return values (comments/docs) of a couple of methods.
Fixed various typos and some additional phpdoc.