Add support for get-unsat-core(s)

[Franck Cassez]

So far only get-interpolants is implemented in the DSL. Add get-unsat-core(s).

[Franck Cassez]

to do:

1. add getUnsatCoreResponses in grammar
2. tests for parsing of responses
3. tests for pretty-printing of command
4. add getUnsatCore in Commands.scala (force named terms?)
5. tests for getUnSatCore (LIA, and other theories)

[Franck Cassez]

Add unSatCoreResponses to grammar. Item 1. in see #16

→ <<cset 6c517ce25c94>>

[Franck Cassez]

Add gteUnsatCore Command. Item 4. see #16

→ <<cset 47c436e6d62a>>

[Franck Cassez]

Add tests for parsing UnsatCoreReponses item 2. see #16

→ <<cset 25286f29d6e6>>

[Franck Cassez]

Add solver options UNSATCORES.

see #16.

→ <<cset 56b1ea666afa>>

[Franck Cassez]

Add tests for command getUnsatCore.

see #16

→ <<cset 2d23f94a7762>>

[Franck Cassez]

Command and a few tests added. Resolved for now.