Last preparations for version 4.5.0.0-Beta. Fixed issue JanKallman#32.…

… Added Multi-targeting project for .Net 3.5, Net 4.0 and .Net Core 2.0 and automatic nuget package build. Added new property for Compatibility.IsWorksheets1Based in ExcelPackage, so the Worksheets collection can be zero based as expected. This will be default in .Net Core. The property can be set from the app.config file or the appsettings.json in .Net Core.

EPPlusTest/WorkSheet.cs

@@ -2900,6 +2900,7 @@ public void Comment()
             pck.SaveAs(new FileInfo(_worksheetPath + "comment.xlsx"));
 
             pck = new ExcelPackage(new FileInfo(_worksheetPath + "comment.xlsx"));
+            pck.Compatibility.IsWorksheets1Based = true;
             var ws2 = pck.Workbook.Worksheets[1];
             ws2.Cells[1, 2].AddComment("Testing", "test1");
             pck.Save();
@@ -2910,12 +2911,14 @@ public void CommentShiftsWithRowInserts()
         {
             InitBase();
             var pck = new ExcelPackage();
+            pck.Compatibility.IsWorksheets1Based = true;
             var ws1 = pck.Workbook.Worksheets.Add("Comment1");
             ws1.Cells[3, 3].AddComment("Testing comment 1", "test1");
             ws1.Cells[4, 3].AddComment("Testing comment 2", "test2");
             var fileInfo = new FileInfo(_worksheetPath + "comment.xlsx");
             pck.SaveAs(fileInfo);
             pck = new ExcelPackage(new FileInfo(_worksheetPath + "comment.xlsx"));
+            pck.Compatibility.IsWorksheets1Based = true;
             ws1 = pck.Workbook.Worksheets[1];
             // Ensure the comments were saved in the correct location.
             Assert.AreEqual("Testing comment 1", ws1.Cells[3, 3].Comment.Text);
@@ -2930,6 +2933,7 @@ public void CommentShiftsWithRowInserts()
             Assert.AreEqual("test2", ws1.Cells[8, 3].Comment.Author);
             pck.Save();
             pck = new ExcelPackage(new FileInfo(_worksheetPath + "comment.xlsx"));
+            pck.Compatibility.IsWorksheets1Based = true;
             ws1 = pck.Workbook.Worksheets[1];
             // Ensure the shifted index is preserved.
             Assert.AreEqual("Testing comment 1", ws1.Cells[3, 3].Comment.Text);
@@ -2943,12 +2947,14 @@ public void CommentShiftsWithColumnInserts()
         {
             InitBase();
             var pck = new ExcelPackage();
+            pck.Compatibility.IsWorksheets1Based = true;
             var ws1 = pck.Workbook.Worksheets.Add("Comment1");
             ws1.Cells[3, 3].AddComment("Testing comment 1", "test1");
             ws1.Cells[3, 4].AddComment("Testing comment 2", "test2");
             var fileInfo = new FileInfo(_worksheetPath + "comment.xlsx");
             pck.SaveAs(fileInfo);
             pck = new ExcelPackage(new FileInfo(_worksheetPath + "comment.xlsx"));
+            pck.Compatibility.IsWorksheets1Based = true;
             ws1 = pck.Workbook.Worksheets[1];
             // Ensure the comments were saved in the correct location.
             Assert.AreEqual("Testing comment 1", ws1.Cells[3, 3].Comment.Text);
@@ -2963,6 +2969,7 @@ public void CommentShiftsWithColumnInserts()
             Assert.AreEqual("test2", ws1.Cells[3, 8].Comment.Author);
             pck.Save();
             pck = new ExcelPackage(new FileInfo(_worksheetPath + "comment.xlsx"));
+            pck.Compatibility.IsWorksheets1Based = true;
             ws1 = pck.Workbook.Worksheets[1];
             // Ensure the shifted index is preserved.
             Assert.AreEqual("Testing comment 1", ws1.Cells[3, 3].Comment.Text);