Various fixes

I added symbols to fix #20 upgraded xdata and changed util.pump() to the latest recommended function as it's been depreciated - all working, and no more errors output to command line.

I then updated to readme to reflect my fork until I figured a pull request would be better and reverted it. 
I've added some improved installation instructions at [https://github.com/Hibby/jsis/wiki/Installation](my wiki) in case I should need to do it again which you may be interested in.

I'm going to continue doing bits of work here and there to the project, I think. Nice visual rewards!