Support for custom domains

[dvoits]

Domain describes structure and semantics of input and output program data.
For each experiment there is one domain.

Input:

• Command line argument with special token to be replaced with an input benchmark file name when run.
• Benchmark files extensions (one or several).

Output:
It describes named values contained in a program output and extracted by two alternative ways:

• "Value" can depend on exit code (specific code corresponds to specific value)
• "Value" is a result of a given regular expression applied to a standard output

Values are represented as a JSON object, one object for each of the benchmarks.

[wintersteiger]

More examples:
F* (custom I/O requirements)
SAT solvers (the "canonical" example is MiniSAT, which follow the SAT competition requirements (there are also many that use parallelism)
Other SMT solvers (very similar to Z3), e.g. those taking part in the SMT Competition