Make simple logger optional

[r0b-]

Would it be possible to make the usage of simple logger optional?
I don't see that much benefits compared to $log here and only have to take care about an additional dependency.

In https://github.com/tombatossals/angular-leaflet-directive it's no dependency (anymore)...

[nmccready]

Comparing to angular-leaflet-directive irrelevant. If you can show me an easy way to optionally load modules and angular services then I can possible do this.

The main motive for it is many people don't want to see any logging by the library unless it is an error. The simple logger makes it easy to keep the libraries logging separate from your application.

Also going for the no dependencies argument is null and void here as ui-leaflet is being broken up and thus will require even more dependencies.

#176

[omeid]

Perhaps you can bring in the simple logger as an internal dependency of ui-leaflet?

[Meekohi]

Serious suggestion: Why not remove the dependency on a special logging library and just have a verbose: true option you can configure this directive with to get additional output?