simplification of paste fix for date fields

No need for self.clipboardCache update, that seems to be done elsewhere.

lib/DataHarmonizer.js

@@ -511,28 +511,38 @@ class DataHarmonizer {
             key: 'paste',
             name: 'Paste',
             disabled: function () {
-              // The only easy way to get system cut+copy buffer contents into
-              // handsontable is to go query the system cut paste buffer every
-              // time the right-click menu is presented, and "Paste" option
-              // enabled.
+              // For now always on, since we can't query whether something is
+              // in system cut/paste buffer without prompting user for ok.
+              return false; 
+            },
+            callback: function () {
+              var plugin = this.getPlugin('copyPaste');
+              this.listen();
+
+              // Due to asynchronous clipboard calls, this has to be in an 
+              // immediate setTimeout()
               setTimeout(async () => {
                 const text = await navigator.clipboard.readText();
                 if (text && text.length) {
-                  self.clipboardCache = text;
+
+                  // An odd issue that with handsontable Paste menu item,
+                  // targeted paste area gets extended a row on each 
+                  // subsequent Paste request.  This doesn't happen if one
+                  // uses CTRL-V instead (but that doesn't work on
+                  // FlatpickrEditor fields unless they are towards end
+                  // of multi-column paste). 
+                  // See https://github.com/handsontable/handsontable/issues/1930
+                  // Solution is to test for and clear out trailing newline.
+
+                  if (text.substr(-1, 1) == '\n')
+                    text = text.slice(0, -1);
+                  //self.clipboardCache = text;
+                  plugin.paste(text);  
                 }
+
               });
 
-              return false; // For now always on, even if cut/copy buffer is empty.
-            },
-            callback: function () {
-              var plugin = this.getPlugin('copyPaste');
-              this.listen();
-              // An odd issue that with handsontable Paste menu item,
-              // targeted paste area gets extended a row on each subsequent
-              // Paste request.  This doesn't happen if one uses CTRL-V
-              // instead (but that doesn't work on FlatpickrEditor fields).
-              // See https://github.com/handsontable/handsontable/issues/1930
-              // Solution is to test for and clear out trailing newline.
+              /*
               if (
                 self.clipboardCache &&
                 self.clipboardCache.length &&
@@ -542,6 +552,7 @@ class DataHarmonizer {
               }
 
               plugin.paste(self.clipboardCache);
+              */
             },
           },
           'remove_row',