[Tweak] BGEE 1.3-ish dialog box

Good news everyone !

After a lot of work, trial and error and experimentation, I finally managed to reproduce a dialog box that behaves almost like in 1.3.

• It only have one scrollbar
  
• If you scroll up, you get the dialog history in the same box
  
• It should work even with bigger font
  
• It should work for BG1EE, SoD and BG2EE
  

Here are some screenshots:


Installation:
- Select all the text from these lines:
`
worldNPCDialogText = ""
to the line before this code:
menu
{
name 'CHARACTER_SELECT'

And replace the selected text with the content of the attached text file.

Changelog:
v0.3: Less text flashing. The scrollbar only appears when you start scrolling.
v0.2: Fix history height computation. Fix out of bound access.
v0.1: Initial release