[bugfix] sepgsql didn't follow the latest core API changes

This patch fixes a few portions on which sepgsql didn't follow the latest
core API changes.

1) Even though the prototype of ProcessUtility_hook was recently changed,
sepgsql side didn't follow this update, so it made build failed.

2) sepgsql internally uses GETSTRUCT() and HeapTupleGetOid() macro
these were moved to htup_details.h, so it needs an additional #include
for "access/htup_defails.h".

3) sepgsql internally used a bool typed variable named "abort".
I noticed it conflicts with ereport macro because it internally expanded to
ereport_domain that contains invocation of "abort()". So, it renamed this
variables to abort_on_violation.

#define ereport_domain(elevel, domain, rest) \
(errstart(elevel, __FILE__, __LINE__, PG_FUNCNAME_MACRO, domain) ? \
(errfinish rest) : (void) 0), \
((elevel) >= ERROR ? abort() : (void) 0)

This does not affect to v9.2, so please apply it on the master branch.

Thanks,
--
KaiGai Kohei <kaigai(at)kaigai(dot)gr(dot)jp>