3 spaces for each opcode
try/except error from asking server for a transaction it can't find
more information printed in the draw() method
write a graphviz/dot file that illustrates the transaction

To view, install and run graphviz: http://www.graphviz.org/Download..php
ignore graph.dot
fixed indendentation in machine.draw docstring
Merge pull request #1 from hackscience/brian-small-fixes

Better visualization