ENYO-1740: Dropbox, implement GET

- implement `FsDropbox.get()`

and also:

- bind() more functions to make `this.log()` actually work everywhere
- remove remaining `console.log()`
- remove always-on error logger
- make traces consistent (always start by `FsDropbox.`

Enyo-DCO-1.1-Signed-off-by: Francois-Xavier KOWALSKI <francois-xavier.kowalski@hp.com>