Set last visual x after SetLoc is called

Fixes #46

cmd/micro/cursor.go

@@ -65,6 +65,7 @@ type Cursor struct {
 // It's just a simple wrapper of FromCharPos
 func (c *Cursor) SetLoc(loc int) {
 	c.x, c.y = FromCharPos(loc, c.v.buf)
+	c.lastVisualX = c.GetVisualX()
 }
 
 // Loc gets the cursor location in terms of character number instead

cmd/micro/view.go

@@ -286,7 +286,8 @@ func (v *View) OpenFile() {
 			messenger.Error(err.Error())
 			return
 		}
-		v.buf = NewBuffer(string(file), filename)
+		buf := NewBuffer(string(file), filename)
+		v.OpenBuffer(buf)
 	}
 }