workaround issue 9634
Issue 10265 - RandomSample fails when passed an InputRange as input

 * Issue fixed by making presence of save() property conditional
   on input being a ForwardRange.
Unittests for randomSample being passed an InputRange.

The assignment of _input = input has been moved from
initialize() to the constructors so as to avoid
problems with nested structs.
Merge pull request #1290 from blackwhale/regex-9634

Workaround issue 9634
Merge pull request #1332 from WebDrake/randomsample-save

Issue 10265 - RandomSample fails when passed an InputRange as input
fix Issue 10268 - std.typecons.Nullable!JSONValue - error instantiating
Merge pull request #1340 from 9rnsr/fix10268

[REG2.063] Issue 10268 - std.typecons.Nullable!JSONValue - error instantiating
Fix Issue 10317 - Remove text(range) check and avoid recursive instantiation bug.
Merge pull request #1343 from AndrejMitrovic/Fix10317

Issue 10317 - Remove text(range) check and avoid recursive instantiation bug.
std.typecons: Fix typo in Rebindable example
Merge pull request #1344 from CyberShadow/patch-4

std.typecons: Fix typo in Rebindable example
Add formatting option to `std.json.toJSON`.

This allows JSON to be used as a temporary serialization format when debugging an application as it becomes human- and diff-readable.

Empty JSON object/array is formatted as "{}"/"[]".
Merge pull request #1263 from denis-sh/std.json-improvements-3

Add formatting option to `std.json.toJSON`.