Move LFSC checker out of the CVC repository. (#222)

LFSC now lives outside of the CVC4 repository and is not part of the CVC4 distribution
anymore. As a consequence, we

+ Add --with-lfsc and --with-lfsc-directory as configure options.
   In the case where CVC4 has not been built with integrated LFSC, all code that interacts with
   LFSC is disabled.

+ Disable proof checking if CVC4_USE_LFSC is not defined.
   Configuring the build with --check-proofs but without --with-lfsc results in an error.

+ Do not call LFSC's cleanup function (but we should in the future).
   LFSC checker segfaults during cleanup on regression testcase regress0/bv/core/bitvec7.smt.
   Disabled call to lfscc_cleanup until the problem in lfscc is fixed.

+ Disable building with LFSC for the distcheck travis build since it is not part of the distribution
   anymore. Further, make distcheck with LFSC would require to call contrib/get-lfsc-checker
   before calling make check on the temp build (the build of the unpacked distribution tar ball).

1 files changed, 0 insertions, 11 deletions

diff --git a/proofs/lfsc_checker/scccode.cpp b/proofs/lfsc_checker/scccode.cpp
deleted file mode 100644
index 19712579c..000000000
--- a/proofs/lfsc_checker/scccode.cpp
+++ /dev/null
@@ -1,11 +0,0 @@
-#include "scccode.h"
-
-void init_compiled_scc(){
-
-}
-
-Expr* run_compiled_scc( Expr* p, std::vector< Expr* >& args ){
-  return NULL;
-}
-
-