pgsql: Added STRING datatype for Informix compatibility mode.

Log Message:
-----------
Added STRING datatype for Informix compatibility mode. This work is
based on a patch send in by Bszrmnyi Zoltn <zb(at)cybertec(dot)at>.

Modified Files:
--------------
pgsql/src/interfaces/ecpg:
ChangeLog (r1.396 -> r1.397)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/ChangeLog?r1=1.396&r2=1.397)
pgsql/src/interfaces/ecpg/compatlib:
Makefile (r1.43 -> r1.44)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/compatlib/Makefile?r1=1.43&r2=1.44)
pgsql/src/interfaces/ecpg/ecpglib:
data.c (r1.42 -> r1.43)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/ecpglib/data.c?r1=1.42&r2=1.43)
descriptor.c (r1.32 -> r1.33)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/ecpglib/descriptor.c?r1=1.32&r2=1.33)
execute.c (r1.85 -> r1.86)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/ecpglib/execute.c?r1=1.85&r2=1.86)
misc.c (r1.49 -> r1.50)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/ecpglib/misc.c?r1=1.49&r2=1.50)
typename.c (r1.14 -> r1.15)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/ecpglib/typename.c?r1=1.14&r2=1.15)
pgsql/src/interfaces/ecpg/include:
ecpgtype.h (r1.37 -> r1.38)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/include/ecpgtype.h?r1=1.37&r2=1.38)
pgsql/src/interfaces/ecpg/pgtypeslib:
Makefile (r1.44 -> r1.45)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/pgtypeslib/Makefile?r1=1.44&r2=1.45)
pgsql/src/interfaces/ecpg/preproc:
ecpg.header (r1.7 -> r1.8)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/preproc/ecpg.header?r1=1.7&r2=1.8)
ecpg.trailer (r1.9 -> r1.10)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/preproc/ecpg.trailer?r1=1.9&r2=1.10)
type.c (r1.83 -> r1.84)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/preproc/type.c?r1=1.83&r2=1.84)
variable.c (r1.49 -> r1.50)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/preproc/variable.c?r1=1.49&r2=1.50)
pgsql/src/interfaces/ecpg/test/compat_informix:
test_informix.pgc (r1.4 -> r1.5)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/compat_informix/test_informix.pgc?r1=1.4&r2=1.5)
pgsql/src/interfaces/ecpg/test/expected:
compat_informix-test_informix.c (r1.17 -> r1.18)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/expected/compat_informix-test_informix.c?r1=1.17&r2=1.18)
compat_informix-test_informix.stderr (r1.13 -> r1.14)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/expected/compat_informix-test_informix.stderr?r1=1.13&r2=1.14)
compat_informix-test_informix.stdout (r1.5 -> r1.6)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/expected/compat_informix-test_informix.stdout?r1=1.5&r2=1.6)