[DAS2] das2 comments

[Allen Day]

> Speaking of which, do the prop fields each need a "name"
> or "description" attribute?  How is a user supposed to
> distinguish between these two images?
> 
> <PROP  ptype = "property/image"
>      href = "http://www.wormbase.org/db/seq/gbrowse_img?name=cTel54X.1" 
> />
> 
> <PROP  ptype = "property/image"
>         mime_type = "image/jpeg"
>         content_encoding = "base64">
> BASE64-ENCODED-DATA-HERE
> </PROP>

I'd like to see something like MAGE's NameValueType used, can we borrow 
from this?

http://www.affymetrix.com/support/technical/manual/netaffx_MAGE_ML_manual.affx

There are formal DTDs and OMG documentation here, but they seem to be 
broken:

http://www.mged.org/Workgroups/MAGE/mage-ml.html

-Allen