Do not include cell separators in grid

Closes #40

src/Spectre.Console.Tests/Unit/Composition/GridTests.cs

@@ -99,13 +99,35 @@ namespace Spectre.Console.Tests.Unit.Composition
         }
 
         [Fact]
-        public void Should_Render_Grid_Column_Padding_Correctly()
+        public void Should_Use_Default_Padding()
+        {
+            // Given
+            var console = new PlainConsole(width: 80);
+            var grid = new Grid();
+            grid.AddColumns(3);
+            grid.AddRow("Foo", "Bar", "Baz");
+            grid.AddRow("Qux", "Corgi", "Waldo");
+            grid.AddRow("Grault", "Garply", "Fred");
+
+            // When
+            console.Render(grid);
+
+            // Then
+            console.Lines.Count.ShouldBe(3);
+            console.Lines[0].ShouldBe("Foo     Bar     Baz  ");
+            console.Lines[1].ShouldBe("Qux     Corgi   Waldo");
+            console.Lines[2].ShouldBe("Grault  Garply  Fred ");
+        }
+
+        [Fact]
+        public void Should_Render_Explicit_Grid_Column_Padding_Correctly()
         {
             // Given
             var console = new PlainConsole(width: 80);
             var grid = new Grid();
             grid.AddColumn(new GridColumn { Padding = new Padding(3, 0) });
-            grid.AddColumns(2);
+            grid.AddColumn(new GridColumn { Padding = new Padding(0, 0) });
+            grid.AddColumn(new GridColumn { Padding = new Padding(0, 3) });
             grid.AddRow("Foo", "Bar", "Baz");
             grid.AddRow("Qux", "Corgi", "Waldo");
             grid.AddRow("Grault", "Garply", "Fred");
@@ -116,8 +138,8 @@ namespace Spectre.Console.Tests.Unit.Composition
             // Then
             console.Lines.Count.ShouldBe(3);
             console.Lines[0].ShouldBe("   Foo   Bar   Baz     ");
-            console.Lines[1].ShouldBe("   Qux    Corgi   Waldo");
+            console.Lines[1].ShouldBe("   Qux   Corgi Waldo   ");
-            console.Lines[2].ShouldBe("   Grault Garply  Fred ");
+            console.Lines[2].ShouldBe("   GraultGarplyFred    ");
         }
 
         [Fact]

src/Spectre.Console/Composition/Grid.cs

@@ -21,6 +21,7 @@ namespace Spectre.Console
                 Border = BorderKind.None,
                 ShowHeaders = false,
                 IsGrid = true,
+                PadRightCell = false,
             };
         }
 
@@ -55,11 +56,14 @@ namespace Spectre.Console
                 throw new ArgumentNullException(nameof(column));
             }
 
+            // Only pad the most right cell if we've explicitly set a padding.
+            _table.PadRightCell = column.Padding != null;
+
             _table.AddColumn(new TableColumn(string.Empty)
             {
                 Width = column.Width,
                 NoWrap = column.NoWrap,
-                Padding = column.Padding,
+                Padding = column.Padding ?? new Padding(0, 2),
                 Alignment = column.Alignment,
             });
         }

src/Spectre.Console/Composition/GridColumn.cs

@@ -20,7 +20,7 @@ namespace Spectre.Console
         /// <summary>
         /// Gets or sets the padding of the column.
         /// </summary>
-        public Padding Padding { get; set; } = new Padding(0, 1);
+        public Padding? Padding { get; set; } = null;
 
         /// <summary>
         /// Gets or sets the alignment of the column.

src/Spectre.Console/Composition/Table.cs

@@ -53,8 +53,14 @@ namespace Spectre.Console
         /// </summary>
         public bool SafeBorder { get; set; } = true;
 
+        // Whether this is a grid or not.
         internal bool IsGrid { get; set; } = false;
 
+        // Whether or not the most right cell should be padded.
+        // This is almost always the case, unless we're rendering
+        // a grid without explicit padding in the last cell.
+        internal bool PadRightCell { get; set; } = true;
+
         /// <summary>
         /// Initializes a new instance of the <see cref="Table"/> class.
         /// </summary>
@@ -279,7 +285,7 @@ namespace Spectre.Console
                         }
 
                         // Pad column on the right side
-                        if (showBorder || (hideBorder && !lastCell) || (IsGrid && !lastCell))
+                        if (showBorder || (hideBorder && !lastCell) || (hideBorder && lastCell && IsGrid && PadRightCell))
                         {
                             var rightPadding = _columns[cellIndex].Padding.Right;
                             if (rightPadding > 0)
@@ -293,7 +299,7 @@ namespace Spectre.Console
                             // Add right column edge
                             result.Add(new Segment(border.GetPart(BorderPart.CellRight)));
                         }
-                        else if (showBorder || (hideBorder && !lastCell))
+                        else if (showBorder)
                         {
                             // Add column separator
                             result.Add(new Segment(border.GetPart(BorderPart.CellSeparator)));