Add an additional command line argument to SR so it does not have to guess which solver to use (fix #505)

[ozgurakgun]

Does this fix it you think @ott2?

[ott2]

Looks good to me:

conjure solve --solver=z3 graph-shortcheaptour-2017070301.essence ../graph-param-weighted/graph-weighted-50-sparsish-connected-2017070301.param

gives

    Savile Row stderr: ERROR: boolector exited with error code:109 and error message:
Error: invalid command line option: -m
For usage information: z3 -h

while

conjure-fix-smt-cli  solve --solver=z3 graph-shortcheaptour-2017070301.essence ../graph-param-weighted/graph-weighted-50-sparsish-connected-2017070301.param

gives

Using cached models.
Savile Row: model000001.eprime ../graph-param-weighted/graph-weighted-50-sparsish-connected-2017070301.param
Running minion for domain filtering.
Running solver: z3

[pwn1]

Sorry, brain not working -- intended to post in the issue, not here.