[ossia-max] a parameter's default value is 'invented' (and returned) when model address changes

[matcham]

If a parameter has no default value, when it's parent model address changes, a default value is invented and sent out.
@type float : returns 0.
@type int : returns 0
@type string : returns an empty string

<pre><code>
----------begin_max5_patcher----------
859.3oc6X0zaiBCD8bpT+OXwkdIMBa9Jom5oUZOuGqVU4.totBrQFSZpp1+6
qwFGRRoTxBrak1dIDLiseya77Fa+5kWLyYMeGovAbC3NvrYupZYltspVlYaX
lSFdWbJtPanSLOKivjNyq+njrSZ9fffkjB.lAHY4xW.ERAksYug4BRgpiXIk
ytOkxHw7RltqHqIrxLJKkH0yDz155x0qSIG0jxPdozZoqsYZhFI70OcMLpYh
wx3GUH4dAIVZbVukQKbmC7WFT8.FpeC4uvE7Scm90kWT8T8X9vIlmejv.Y7D
RJ.mjnXgBP7iX1FEWcC.CRHOfKSkfs3zRBfV.thx1pFHRxUNcSL8fEB6hEfQ
dU9smq9WeeMI3NHRfQdVMuukCxUKEjfay44k4.3v8KXW9EZkNrF.C0QWWs+g
PCxwxTgM7FR6HG0Nxgsgbz9gHgyjBRdJN93E2ssd03J0qWCNvgrcxLsxWxIl
d33z7sMBbBkXx0Zxp1DyS4Bi0tKBWFhh7CbWsz0aEBMumMAODC0CIxNl5tX+
4DKefllps9dKlafYaVo+ENtn8jQ+Lw8DPeMCNtTxOLrUEwayL1FixHJ5crHW
vy4hJMWyvDL5o17hBJdQNVfyHRh.j8xOzB+faqhrmVE3bD9ONaB0V1jeOzA7
QPsN.Rqx6E1cZybcpymcAPud32dgASm92dGycvRhACPQzyy+KEwuTD+rqH98
pbesbH8fn4HqE51CMACqX0DlXsv2UyvtM3mHX10YT0tgIoCVFYUma32uYmtP
OT+TK9rWDHp6.9Jy9489aTDXwfCeg+QUAPlHZD5qp.+eTE37k26Ywjw+b+L9
wms2YBtliN2+quQnCB8MxdvQ3VN5eMuukxw1pdOT8+IptGpGpfP2kli.38O7
H.FJp9hfXRthEFAJo0KY3iKEF5eF6C3MjgwXMpO85C0yX0GNghJ3khX6HZO6
F3foMgTHoLrMy8tl6KA.O.bhDhVcoiD1wFBvisZODfiADb6CDBlRRnWHvaB4
.Te.P3DRA8B.QSHCrpWqCMF0dpHNOeKQTT2CyLojkdxTJd4by6Tl4cSQQGAY
K01EiniCVnzKjJwhRgY2G6Bqqw3TobIXkTqSW4qUSsV4ioz8Kxq2xlVg7xKT
F7a.G5UjsA
-----------end_max5_patcher-----------
</code></pre>

I would expect it to not return anything if there's no default value specified, and if no no value has been set yet.

it may be related to #703 ?
(I agree that if a value has been set to the parameter, it should be return when the model address changes.)