Print Default Values of String-to-String in Sorted Order

[vaguecoder]

Motivation

Issue 362 reported by @SOF3

Changes

Sort keys before stringifying string-to-string flag values.

Summary

String-to-string default values in usage would print in sorted order of keys. Eg. --foo stringToString usage (default [a=b,c=d]) In the example as per #362, now, the order will be always default [a=b,c=d]

Related Issues

Closes #362

[SOF3]

what about string to other types like integers?

[vaguecoder]

what about string to other types like integers?

Yes, there are another 2 places. Let this PR be a PoC. We can have set of issue-PR to address those.

1. String to int
2. String to int64