Split plpython.c into smaller pieces

This moves the code around from one huge file into hopefully logical
and more manageable modules.  For the most part, the code itself was
not touched, except: PLy_function_handler and PLy_trigger_handler were
renamed to PLy_exec_function and PLy_exec_trigger, because they were
not actually handlers in the PL handler sense, and it makes the naming
more similar to the way PL/pgSQL is organized.  The initialization of
the procedure caches was separated into a new function
init_procedure_caches to keep the hash tables private to
plpy_procedures.c.

Jan Urbański and Peter Eisentraut

Author: petere

src/pl/plpython/Makefile

@@ -38,7 +38,19 @@ rpathdir = $(python_libdir)
 
 NAME = plpython$(python_majorversion)
 
-OBJS = plpython.o
+OBJS = \
+	plpy_cursorobject.o \
+	plpy_elog.o \
+	plpy_exec.o \
+	plpy_main.o \
+	plpy_planobject.o \
+	plpy_plpymodule.o \
+	plpy_procedure.o \
+	plpy_resultobject.o \
+	plpy_spi.o \
+	plpy_subxactobject.o \
+	plpy_typeio.o \
+	plpy_util.o
 
 DATA = $(NAME)u.control $(NAME)u--1.0.sql $(NAME)u--unpackaged--1.0.sql
 ifeq ($(python_majorversion),2)
@@ -177,7 +189,7 @@ endif # can't build
 # distprep and maintainer-clean rules should be run even if we can't build.
 
 # Force this dependency to be known even without dependency info built:
-plpython.o: spiexceptions.h
+plpython_plpy.o: spiexceptions.h
 
 spiexceptions.h: $(top_srcdir)/src/backend/utils/errcodes.txt generate-spiexceptions.pl
 	$(PERL) $(srcdir)/generate-spiexceptions.pl $< > $@

src/pl/plpython/nls.mk

@@ -1,7 +1,8 @@
 # src/pl/plpython/nls.mk
 CATALOG_NAME     = plpython
 AVAIL_LANGUAGES  = de es fr it ja pt_BR ro tr zh_CN zh_TW
-GETTEXT_FILES    = plpython.c
+GETTEXT_FILES    = plpy_cursorobject.c plpy_elog.c plpy_exec.c plpy_main.c plpy_planobject.c plpy_plpymodule.c \
+                   plpy_procedure.c plpy_resultobject.c plpy_spi.c plpy_subxactobject.c plpy_typeio.c plpy_util.c
 GETTEXT_TRIGGERS = $(BACKEND_COMMON_GETTEXT_TRIGGERS) PLy_elog:2 PLy_exception_set:2 PLy_exception_set_plural:2,3
 GETTEXT_FLAGS    = $(BACKEND_COMMON_GETTEXT_FLAGS) \
     PLy_elog:2:c-format \