Java, C#: Add experimental notification to the shortenMantissa function

Author: agdavydov81

csharp/EPAM.Deltix.DFP/Decimal64.cs

@@ -810,6 +810,7 @@ public Decimal64 RoundToNearestTiesToEven(Decimal64 multiple)
 		}
 
 		/// <summary>
+		/// This function is experimental.
 		/// Returns a <code>DFP</code> number in some neighborhood of the input value with a maximally
 		/// reduced number of digits.
 		/// Explanation:

java/dfp/src/main/java/com/epam/deltix/dfp/Decimal64.java

@@ -716,6 +716,7 @@ public Decimal64 average(final Decimal64 other) {
     /// region Rounding
 
     /**
+     * This function is experimental.
      * Returns a {@code DFP} number in some neighborhood of the input value with a maximally
      * reduced number of digits.
      * Explanation:

java/dfp/src/main/java/com/epam/deltix/dfp/Decimal64Utils.java

@@ -851,6 +851,7 @@ public static long mean(@Decimal final long a, @Decimal final long b) {
     /// region Rounding
 
     /**
+     * This function is experimental.
      * Returns a {@code DFP} number in some neighborhood of the input value with a maximally
      * reduced number of digits.
      * Explanation: