Add missing schema (bug #3216)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@4701 65c4cc65-6c06-0410-ace0-fbb531ad65f3

doc/README.odbcstorage

+ODBC Voicemail Storage
+======================
+
+ODBC Storage allows you to store voicemail messages within a database 
+instead of using a file.  This is *not* a full realtime engine and 
+*only* supports ODBC.  The table description for the "voicemessages" 
+table is as follows:
+
++--------------+-------------+------+-----+---------+-------+
+| Field        | Type        | Null | Key | Default | Extra |
++--------------+-------------+------+-----+---------+-------+
+| msgnum       | int(11)     | YES  |     | NULL    |       |
+| dir          | varchar(80) | YES  | MUL | NULL    |       |
+| context      | varchar(80) | YES  |     | NULL    |       |
+| macrocontext | varchar(80) | YES  |     | NULL    |       |
+| callerid     | varchar(40) | YES  |     | NULL    |       |
+| origtime     | varchar(40) | YES  |     | NULL    |       |
+| duration     | varchar(20) | YES  |     | NULL    |       |
+| recording    | longblob    | YES  |     | NULL    |       |
++--------------+-------------+------+-----+---------+-------+
+
+The database name (from /etc/asterisk/res_odbc.conf) is in the 
+"odbcstorage" variable in the general section.
+
+Mark