Fixed ECLiPSe-CLP interface bugs; found problem with GC.

ECLiPSe-CLP doesn't like Boehm GC.
Property 2 leads to segfault.
Added example binaries to .gitignore.
Fixed: query_ennf() didn't propagate negations properly.

The pushed-inside negation was essentially ignored at literal level.
pred_t is long int now; introduced MAX_PRED.

The only practical advantage over int is that it has the same size as
void* and we can thus use it with our containers.

Like MAX_STD_NAME, BATs define a MAX_PRED now.
Fixed (possibly): garbage collection issue with ECLiPSe-CLP.

When NO_GC is defined before including memory.h, normal malloc() is used
instead of GC_MALLOC(). It looks like it's enough if ec_interface.c and
thus libEclipseESBL doesn't use Boehm GC; libESBL may still do.
ECLiPSe-CLP correctly handles non-BAT predicates.

Like standard names, they are mapped to distinct new predicates.
Added email address to a few headers.