New approach for calculating and passing stdout stuff to the checker.

Breaks backward compatibility:

1. There is no dops_implied_stdout function anymore.
2. Checkers will receive as argv[2] and argv[3] the string corresponding to stdout and stderr at that time.
3. Pseudo-diskops corresponding to stdout and stderr are produced.
4. Checker specification in the configuration file can now only contain a single executable file name. No redirections etc.
Adding the auto_run config option. Also, using appends to print to replay_output, thereby also storing any exception that might be happening.
Adding the expanded_atomicity option for generating diskops. Also, changing the way some diskops are generated:

1. During the rename or unlink calls, the truncate now happen before a link is removed.
2. For appends and truncates, the first set of zero writes are no longer generated without expanded_atomicity. With expanded_atomicity, different things are generated.
Bunch of small changes, mostly for improving performance:
1. Added dops_include()
2. Even without threads, diskops replay uses cached mode now.
3. Added _export()
4. Added micro_len()
5. The configuration file is now supplied with __file__
Converting simulate_crashes into an importable-library, and defining various sets of micro-ops and diskops that can be used when other people import libraries.
Adding the standardized specifier and error reporter