cosmetic: sql/hlr.sql: move comments

By moving the comments inside the table row definitions, they are dumped back
during 'sqlite3 hlr.db .dump'. When they are between SQL statements like before
this patch, the comments are lost.

Tweak wording.

Change-Id: I280c2e2d3e9b7f1dc632722724d9e1c54d041820

sql/hlr.sql

@@ -1,6 +1,5 @@
---modelled roughly after TS 23.008 version 13.3.0
-
 CREATE TABLE IF NOT EXISTS subscriber (
+-- OsmoHLR's DB scheme is modelled roughly after TS 23.008 version 13.3.0
 	id		INTEGER PRIMARY KEY,
 	-- Chapter 2.1.1.1
 	imsi		VARCHAR(15) UNIQUE NOT NULL,
@@ -45,8 +44,8 @@ CREATE TABLE IF NOT EXISTS subscriber_apn (
 	apn		VARCHAR(256) NOT NULL
 );
 
--- Chapter 2.1.3
 CREATE TABLE IF NOT EXISTS subscriber_multi_msisdn (
+-- Chapter 2.1.3
 	subscriber_id	INTEGER,		-- subscriber.id
 	msisdn		VARCHAR(15) NOT NULL
 );