Add Mod + Shift + c/v and no selclear.

Thanks to Alex Pilon <alp@alexpilon.ca>!

Now there is a distinction between the primary and clipboard selection. With
Mod + Shift + c/v the clipboard is handled. The old Insert behavious does
reside.

config.def.h

@@ -119,6 +119,8 @@ static Shortcut shortcuts[] = {
 	{ MODKEY|ShiftMask,     XK_Home,        xzoomreset,     {.i =  0} },
 	{ ShiftMask,            XK_Insert,      selpaste,       {.i =  0} },
 	{ MODKEY|ShiftMask,     XK_Insert,      clippaste,      {.i =  0} },
+	{ MODKEY|ShiftMask,     XK_C,           clipcopy,       {.i =  0} },
+	{ MODKEY|ShiftMask,     XK_V,           clippaste,      {.i =  0} },
 	{ MODKEY,               XK_Num_Lock,    numlock,        {.i =  0} },
 };