Javadoc: Add missing @SInCE 1.7.

Author: Gary Gregory

src/main/java/org/apache/commons/csv/CSVFormat.java

@@ -884,6 +884,7 @@ public String format(final Object... values) {
      * Returns true if and only if duplicate names are allowed in the headers.
      * 
      * @return whether duplicate header names are allowed
+     * @since 1.7
      */
     public boolean getAllowDuplicateHeaderNames() {
 		return allowDuplicateHeaderNames;
@@ -1691,7 +1692,8 @@ public CSVFormat withAllowDuplicateHeaderNames() {
      * Returns a new {@code CSVFormat} with duplicate header names behavior set to the given value.
      * 
      * @param allowDuplicateHeaderNames the duplicate header names behavior, true to allow, false to disallow.
-     * @return a new {@code CSVFormat} with duplicate header names behavior set to the given value
+     * @return a new {@code CSVFormat} with duplicate header names behavior set to the given value.
+     * @since 1.7
      */
     public CSVFormat withAllowDuplicateHeaderNames(final boolean allowDuplicateHeaderNames) {
     	return new CSVFormat(delimiter, quoteCharacter, quoteMode, commentMarker, escapeCharacter,