ES6 nit-picking: property shorthand, static class-side methods, default parameter values

Karma results:

```
INFO [watcher]: Changed file "/Users/rwaldron/clonez/diary.js/src/diary.js".
Chrome 32.0.1700 (Mac OS X 10.9.1): Executed 8 of 8 SUCCESS (0.299 secs / 0.004 secs)
```

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>