pgsql: Added missing constuctor/destructor for interval and date.

Log Message:
-----------
Added missing constuctor/destructor for interval and date.

Modified Files:
--------------
pgsql/src/interfaces/ecpg:
ChangeLog (r1.334 -> r1.335)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/ChangeLog.diff?r1=1.334&r2=1.335)
pgsql/src/interfaces/ecpg/include:
pgtypes_date.h (r1.9 -> r1.10)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/include/pgtypes_date.h.diff?r1=1.9&r2=1.10)
pgtypes_interval.h (r1.11 -> r1.12)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/include/pgtypes_interval.h.diff?r1=1.11&r2=1.12)
pgsql/src/interfaces/ecpg/pgtypeslib:
datetime.c (r1.30 -> r1.31)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/pgtypeslib/datetime.c.diff?r1=1.30&r2=1.31)
interval.c (r1.34 -> r1.35)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/pgtypeslib/interval.c.diff?r1=1.34&r2=1.35)
pgsql/src/interfaces/ecpg/test/expected:
pgtypeslib-dt_test2.c (r1.6 -> r1.7)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/expected/pgtypeslib-dt_test2.c.diff?r1=1.6&r2=1.7)
pgtypeslib-dt_test2.stdout (r1.3 -> r1.4)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/expected/pgtypeslib-dt_test2.stdout.diff?r1=1.3&r2=1.4)
pgsql/src/interfaces/ecpg/test/pgtypeslib:
dt_test2.pgc (r1.3 -> r1.4)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/pgtypeslib/dt_test2.pgc.diff?r1=1.3&r2=1.4)