Remove fork()/exec() and only do fork(). Small cleanups.

src/backend/bootstrap/bootstrap.c

src/backend/executor/execQual.c

src/backend/libpq/pqcomm.c

src/backend/port/dynloader/bsdi.h

src/backend/postmaster/postmaster.c

src/backend/storage/ipc/ipc.c

src/backend/storage/ipc/ipci.c

src/backend/storage/smgr/mm.c

src/backend/storage/smgr/smgr.c

src/backend/tcop/postgres.c

src/backend/utils/error/excabort.c

src/backend/utils/init/globals.c

src/backend/utils/init/miscinit.c

src/backend/utils/init/postinit.c

src/include/libpq/libpq.h

src/include/miscadmin.h

src/include/storage/ipc.h

src/include/tcop/tcopprot.h

src/interfaces/Makefile