Remove the double \n\n in send EchoCmd in Interpreters.

[Franck Cassez]

In the latest releases of CVC4 1.6, it is necessary to send two "\n" after the echo command for it to get processed by the solver. A temporary solution is to alter the interpreter and send two "\n".

When CVC4 1.6 (or another release) is fixed, we can revert back to a single "\n".

The change is in the file Interpreters.scala, method evalCmdInSolver.

[Franck Cassez]

Add tests for terms generated by conversions from FPBV to uBV and sBV.

closes #11 closes #24

→ <<cset b3ca8db6a292>>

[Franck Cassez]

Re-open due to wrong comments in one commit that closed it.