Move the dll into designer, add rounded corners.

Author: ohmypxl

src/MainForm.Designer.cs

@@ -1,5 +1,6 @@
 using System;
 using System.IO;
+using System.Runtime.InteropServices;
 using System.Windows.Forms;
 
 using sxlib;
@@ -13,11 +14,6 @@ public partial class SkidWareForm : Form
         private const int WM_NCLBUTTONDOWN = 0xA1;
         private const int HT_CAPTION = 0x2;
 
-        [System.Runtime.InteropServices.DllImport("user32.dll")]
-        private static extern int SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);
-        [System.Runtime.InteropServices.DllImport("user32.dll")]
-        private static extern bool ReleaseCapture();
-
         public SkidWareForm()
         {
             InitializeComponent();