Rethink naming of contrib/intagg extension.

Initially it was called int_aggregate after the old SQL file, but since
the documentation just says "intagg" and that's also the directory name,
let's conform to that instead.

contrib/intagg/Makefile

 # contrib/intagg/Makefile
 
-EXTENSION = int_aggregate
-DATA = int_aggregate--1.0.sql int_aggregate--unpackaged--1.0.sql
+EXTENSION = intagg
+DATA = intagg--1.0.sql intagg--unpackaged--1.0.sql
 
 ifdef USE_PGXS
 PG_CONFIG = pg_config

contrib/intagg/int_aggregate--unpackaged--1.0.sql

-/* contrib/intagg/int_aggregate--unpackaged--1.0.sql */
-
-ALTER EXTENSION int_aggregate ADD function int_agg_state(internal,integer);
-ALTER EXTENSION int_aggregate ADD function int_agg_final_array(internal);
-ALTER EXTENSION int_aggregate ADD function int_array_aggregate(integer);
-ALTER EXTENSION int_aggregate ADD function int_array_enum(integer[]);

contrib/intagg/int_aggregate--1.0.sql → contrib/intagg/intagg--1.0.sql

-/* contrib/intagg/int_aggregate--1.0.sql */
+/* contrib/intagg/intagg--1.0.sql */
 
 -- Internal function for the aggregate
 -- Is called for each item in an aggregation

contrib/intagg/intagg--unpackaged--1.0.sql

+/* contrib/intagg/intagg--unpackaged--1.0.sql */
+
+ALTER EXTENSION intagg ADD function int_agg_state(internal,integer);
+ALTER EXTENSION intagg ADD function int_agg_final_array(internal);
+ALTER EXTENSION intagg ADD function int_array_aggregate(integer);
+ALTER EXTENSION intagg ADD function int_array_enum(integer[]);

contrib/intagg/int_aggregate.control → contrib/intagg/intagg.control

-# int_aggregate extension
+# intagg extension
 comment = 'integer aggregator and enumerator (obsolete)'
 default_version = '1.0'
 relocatable = true