Support Scroll to Bottom

(NB Thanks VisualG at CodeProject, see http://www.codeproject.com/Articles/335909/Embedding-a-Console-in-a-C-Application?msg=4642047#xx4642047xx)

This responce is a little late i know, but there are probably more people that want to know how to do this.

if u want the richtextbox to auto scroll down when text is appended u can use this code

```
[DllImport("user32.dll")]
private static extern IntPtr SendMessage(IntPtr window, int message, int wparam, int lparam);

private const int SbBottom = 0x7;
private const int WmVscroll = 0x115;

//call this in a method after appending text in the richtextbox
//dont forget to change richtextbox1 with youre richtextboxcontrol

SendMessage(richtextbox1.Handle, WmVscroll, SbBottom, 0x0);
```