pgsql: Improve translatability of error messages for external modules by

Log Message:
-----------
Improve translatability of error messages for external modules by tweaking
the ereport macro. Included in this commit are enough files for starting
plpgsql, plpython, plperl and pltcl translations.

Modified Files:
--------------
pgsql/src/backend/utils/error:
elog.c (r1.206 -> r1.207)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/error/elog.c?r1=1.206&r2=1.207)
pgsql/src/backend/utils/init:
miscinit.c (r1.167 -> r1.168)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/init/miscinit.c?r1=1.167&r2=1.168)
pgsql/src/include:
miscadmin.h (r1.202 -> r1.203)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/miscadmin.h?r1=1.202&r2=1.203)
pgsql/src/include/utils:
elog.h (r1.94 -> r1.95)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/elog.h?r1=1.94&r2=1.95)
pgsql/src/pl/plperl:
plperl.c (r1.139 -> r1.140)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plperl/plperl.c?r1=1.139&r2=1.140)
pgsql/src/pl/plpgsql/src:
pl_handler.c (r1.40 -> r1.41)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/pl_handler.c?r1=1.40&r2=1.41)
plpgsql.h (r1.101 -> r1.102)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/plpgsql.h?r1=1.101&r2=1.102)
pgsql/src/pl/plpython:
plpython.c (r1.112 -> r1.113)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpython/plpython.c?r1=1.112&r2=1.113)
pgsql/src/pl/tcl:
pltcl.c (r1.121 -> r1.122)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/tcl/pltcl.c?r1=1.121&r2=1.122)

Added Files:
-----------
pgsql/src/pl/plperl:
nls.mk (r1.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plperl/nls.mk?rev=1.1&content-type=text/x-cvsweb-markup)
pgsql/src/pl/plpgsql/src:
nls.mk (r1.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/nls.mk?rev=1.1&content-type=text/x-cvsweb-markup)
pgsql/src/pl/plpython:
nls.mk (r1.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpython/nls.mk?rev=1.1&content-type=text/x-cvsweb-markup)
pgsql/src/pl/tcl:
nls.mk (r1.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/tcl/nls.mk?rev=1.1&content-type=text/x-cvsweb-markup)