Add convenience method to Json struct to output pretty strings

[jniehus]

added convenience method to Json struct to output pretty strings and also added level (default == 0) parameter to "toPrettyJson()" overload

[s-ludwig]

I get the feeling that all the Json->string conversion requires a bit of a clean up. Maybe toJson/``toPrettyJsonshould getwriteJsonString`and `writePrettyJsonString` with your `Json.toPrettyString` added and the old names kept as a deprecated alias...

Btw. do you see/have an actual use for the level parameter? My original indention was more of an internal nature - it would have been cleaner to hide it in an inner function. But of course it doesn't hurt as a public option either.

[jniehus]

Yea that sounds good.

Btw. do you see/have an actual use for the level parameter?

I could live without it. I used it when dumping test results and debugging info back to the console. Once everything thing starts working, i just git rid of it and dump things to mongodb. For my 1 use case, 0 indention is good enough.

[s-ludwig]

Hm at least it is a use case. I'm really struggling with a decision here, because

1. Technically it's perfectly fine to add it and also doesn't really complicate the interface
2. It might lead to the wish to customize the output even more (indentation style, line breaks etc) and then either more parameters get added or the parameter needs to get changed to a struct (breaking backwards compatibility)

[s-ludwig]

I'll just merge it in with the parameter for now, though, and defer the final decision a bit...

[s-ludwig]

Okay the renamed functions are in 2948051 now.