Separate attribute for custom transaction isolation

Request is to create a list of allowed values for "transaction-isolation" and use a separate alternative attribute for the edge cases where a custom value is desired.

hbraun: take a look at https://gist.github.com/4594850
[08:01am] hbraun: the description contains a list of allowed values
[08:01am] hbraun: do we have a formalised way to describe this within the model?
[08:02am] hbraun: https://community.jboss.org/wiki/DetypedDescriptionOfTheAS7ManagementModel doesn't contain it
[08:03am] bstansberry: hbraun: use https://docs.jboss.org/author/display/AS71/Description+of+the+Management+Model now
[08:03am] hbraun: tnx
[08:03am] bstansberry: which is the same thing, but in the more maintained stream
[08:03am] bstansberry: hbraun: but yes, it should be formally described
[08:04am] bstansberry: hbraun: under "Arbitrary Descriptors" see "allowed"
[08:05am] hbraun: bstansberry: great, exactly what I was looking for
[08:05am] hbraun: I knew we had something like this
[08:05am] bstansberry: hbraun: so if that's missing it's a bug
[08:06am] bstansberry: there's a standard way of adding that for attributes backed by an enum
[08:08am] bstansberry: hbraun: where is that attribute? datasource subsystem?
[08:08am] hbraun: yeah
[08:10am] bstansberry: hbraun: ok, the reason "allowed" isn't set is because custom levels are supported
[08:11am] hbraun: hm
[08:11am] hbraun: i would prefer an extra attribute for customisation
[08:11am] hbraun: and let them be mutual exclusive
[08:11am] hbraun: cases like this prevent a successful move to a dynamic GUI
[08:13am] hbraun: the less ambiguity the better
[08:13am] hbraun: especially in the DMR model