More cleaning up and removed some duplicates.

src/interfaces/ecpg/ChangeLog

src/interfaces/ecpg/pgtypeslib/dt.h

src/interfaces/ecpg/pgtypeslib/dt_common.c

src/interfaces/ecpg/pgtypeslib/interval.c

src/interfaces/ecpg/pgtypeslib/timestamp.c

src/interfaces/ecpg/preproc/Makefile

src/interfaces/ecpg/preproc/c_keywords.c

src/interfaces/ecpg/preproc/ecpg_keywords.c

src/interfaces/ecpg/preproc/extern.h

src/interfaces/ecpg/preproc/keywords.c

src/interfaces/ecpg/preproc/pgc.l

src/interfaces/ecpg/preproc/preproc.y

src/interfaces/ecpg/preproc/type.c