NLS: Use msgmerge/xgettext --no-wrap and --sort-by-file

The option --no-wrap prevents wars with (most?) editors about proper
line wrapping.  --sort-by-file ensures consistent file order, for
easier diffing.

src/nls-global.mk

@@ -40,7 +40,11 @@ ALL_PO_FILES = $(addprefix po/, $(addsuffix .po, $(AVAIL_LANGUAGES)))
 MO_FILES = $(addprefix po/, $(addsuffix .mo, $(LANGUAGES)))
 
 ifdef XGETTEXT
-XGETTEXT += -ctranslator --copyright-holder='PostgreSQL Global Development Group' --msgid-bugs-address=pgsql-bugs@postgresql.org
+XGETTEXT += -ctranslator --copyright-holder='PostgreSQL Global Development Group' --msgid-bugs-address=pgsql-bugs@postgresql.org --no-wrap --sort-by-file
+endif
+
+ifdef MSGMERGE
+MSGMERGE += --no-wrap --sort-by-file
 endif
 
 # _ is defined in c.h, so it's global