Change function names to camelCase

[CelliesProjects]

To get more consistent the function names will be changed to camelCase.

The old names will be dropped in 3.0.0.

[Frank-Bemelman]

If you do change the callbacks, don't forget to change the examples too. Sure it would give a compile error if people download a version with this changes, but imo not so bad, as it is quite obvious when that happens and how to fix it. I added an extra callback myself, to get more information on HTTP return code such as 404 and 503, invalid url, unsupported mime and a few others.
If you want I could do a pull request.

[CelliesProjects]

@Frank-Bemelman This pr will have to brew somewhat longer. And thanks for the hint about the examples.

I saw you forked and added a callback. I am interested but very busy irl so might not review or respond promptly.

[Frank-Bemelman]

Sure, no rush here. The way my radio globe works, is that it first collects a list of available radio stations for the position of the globe and latttude pointer. And then picks a random station from that list, and picks the next station when it fails. Since I have so many fails, caused by all sorts of reasons, I added that callback just to collect all the stubborn ones. It is only a tool, it doesn't fix or improve anything of course.