Add back button about renjs-v2 HOT 1 OPEN

I've wanted to have this kind of feature, or a text log for a while, but with the new GUI, the previous attempts are probably lacking a bit.
Currently every time a text and say actions, the text is saved in a log in the TextManager, along with the character name. This is not enough now because the text action have more parameters, like namebox and messagebox.

What I think we need to implement this taks:

• Save the say and text task themselves with all parameters in the textLog.
• Add button action bindings (can be bind to mouse wheel too?) for going back and forth in the text log:
  • Pause the game if not paused
  • Update the text log index
  • Show text/say action without animation
• Add button action binding to continue with the game:
  • Clear GUI (hide message and name boxes)
  • Reset text log index
  • Unpause game

from renjs-v2.