Pyccolo

-------------------
* Provide non-context manager variants of tracing-related contexts;

-------------------
* Add 'exit_module' event;
* Use deferred evaluation variants for all 'before expr' events;
* Improve AST bookkeeping;
* Add FutureTracer under pyccolo.examples;
* Fix bug where starred expressions weren't traced if used as literal elements;

-------------------
* Fix packaging issue after new configuration;

-------------------
* Move configuration out of setup.py;

-------------------
* Default to all tracers in stack for package-level tracing enabled / disabled context managers;
* Omit instrumentating the AST of statements underneath "with pyc.tracing_disabled()" bocks;
* Add SkipAll return value;
* Improve reentrancy for sys events;

-------------------
* Expose logic for resolving tracer class based on module path;