v0.9.0

Changes:

• More robust manipulation of execution graphs
• Added optimization for ifs with constant predicates
• Added --max-execution-time for long running methods
• Added ExecutionGrapher which gives a GraphViz compatible DOT file for an execution graph. Screen shots below.
• Improved dead code detection
• Mostly eliminated method re-execution during optimization
• Many more tests and bug fixes

Here's a small example method graph to show what ExecutionGrapher does. Each node in the graph is the execution of some instruction, along with all the relevant context at that point. This is before optimization:

Graph after optimization: