check error messages for `This functionality will be improved in later versions of libSBML.`

[fbergmann]

Validating a file, i saw the following error message:

  <message lang='en_US'><![CDATA[(LibSBML Check #99404) LibSBML expected to read the annotation into a ModelHistory object. 
Unfortunately, some attributes were not present or correct and the resulting ModelHistory object will not correctly produce the 
annotation.  This functionality will be improved in later versions of libSBML.

Reference: L2V4 Section 6.3

 An invalid ModelHistory element has been stored.
]]></message>

we should not announce things like that in error messages. I think we better remove statements like that. And just improve things once we get around to doing them.

[luciansmith]

Agreed!