std.manifestJsonEx - different arguments count than what documented

[dohnto]

Hi, according to official docs there should be a std.manifestJsonEx function which accept 4 arguments

std.manifestJsonEx(value, indent, newline, key_val_sep)

Sounds good. Looking at the original implementation it is the case:

manifestJsonEx(value, indent, newline='\n', key_val_sep=': ')::

But in go's implementation, the function accepts only 2 arguments

  "manifestJsonEx":     g.newSimpleFuncType(stringType, "value", "indent"),

I believe, it should be aligned with the docs.