JBMC Tool wrapper

[peterschrammel]

Together with coming PRs to the SV-COMP repos, this will allow us to run JBMC (and also JayHorn and JPF)
on benchexec.

Benchmarks are coming here:

• https://github.com/peterschrammel/sv-benchmarks/tree/java-benchmarks

Benchmark-Defs:

• https://github.com/peterschrammel/sv-comp/tree/jbmc

Basic benchexec tool wrappers and introduction of "assert" property:

• https://github.com/peterschrammel/benchexec/tree/jbmc

[tautschnig]

Looks fine to me. Not yet approving per the do-not-merge request.

[peterschrammel]

PRs filed:

• Java Benchmarks for Java Category sosy-lab/sv-benchmarks#565
• Tool wrappers for JPF, Jayhorn and JBMC sosy-lab/benchexec#293
• JBMC tool sosy-lab/sv-comp#82

Evaluation results: https://pschrammel.bitbucket.io/schrammel-it/research/sv-comp-java-2018/