pgsql-server: Made sure SET DESCRIPTOR accepts all data types including

Log Message:
-----------
Made sure SET DESCRIPTOR accepts all data types including constants.

Modified Files:
--------------
pgsql-server/src/interfaces/ecpg:
ChangeLog (r1.270 -> r1.271)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/interfaces/ecpg/ChangeLog.diff?r1=1.270&r2=1.271)
pgsql-server/src/interfaces/ecpg/ecpglib:
data.c (r1.25 -> r1.26)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/interfaces/ecpg/ecpglib/data.c.diff?r1=1.25&r2=1.26)
descriptor.c (r1.9 -> r1.10)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/interfaces/ecpg/ecpglib/descriptor.c.diff?r1=1.9&r2=1.10)
execute.c (r1.35 -> r1.36)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/interfaces/ecpg/ecpglib/execute.c.diff?r1=1.35&r2=1.36)
extern.h (r1.9 -> r1.10)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/interfaces/ecpg/ecpglib/extern.h.diff?r1=1.9&r2=1.10)
pgsql-server/src/interfaces/ecpg/include:
ecpglib.h (r1.61 -> r1.62)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/interfaces/ecpg/include/ecpglib.h.diff?r1=1.61&r2=1.62)
pgsql-server/src/interfaces/ecpg/preproc:
preproc.y (r1.290 -> r1.291)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/interfaces/ecpg/preproc/preproc.y.diff?r1=1.290&r2=1.291)
variable.c (r1.35 -> r1.36)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/interfaces/ecpg/preproc/variable.c.diff?r1=1.35&r2=1.36)
pgsql-server/src/interfaces/ecpg/test:
test_desc.pgc (r1.1 -> r1.2)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/interfaces/ecpg/test/test_desc.pgc.diff?r1=1.1&r2=1.2)