Do not trigger didSetProperty if value is unchanged.

Also, fix determination of oldValue (previous a falsy value would not be
found in `this._attributes`).
Pass arguments to `options.defaultValue` if a function.
Merge pull request #1677 from rjackson/only_set_different_values

Do not trigger didSetProperty if value is unchanged.
Merge pull request #1694 from rjackson/pass-arguments-to-defaultValue

Pass arguments to `options.defaultValue` if a function.
Remove incorrect return documentation on store#pushPayload
Merge pull request #1695 from bmac/fix-pushpayload-docs

Remove incorrect return documentation on store#pushPayload
lazy create errors object on models
postinstall bower install
add `grunt server`, and ensure the server(dev) version builds tests, so you can run tests
once is already saved off at the top of the file
Merge pull request #1696 from tchak/lazy-errors

lazy create errors object on models
misc cleanup
allow connect port to be configurable