[Runtime.vicfg] Fixes for At(), RAt() and similar functions. Warning, string:IndexOf() for some strange reason returns zero (not -1) when the search string is empty.
[Runtime.vicfg] Fixes for At(), RAt() and similar functions. Warning, string:IndexOf() for some strange reason returns zero (not -1) when the search string is empty.

X-Sharp/XSharpPublic,X-Sharp/XSharpPublic,X-Sharp/XSharpPublic,X-Sharp/XSharpPublic,X-Sharp/XSharpPublic