Bean names and the Attribute resolution schema files

[Rod Widdowson]

Daniel asked me to finish off the template handling code for the RDBMS
DataConnector.  We have previously decided (I believe) to do away with the
TemplateEngine concept from V2 (which I don't really understand the
motivation for) and instead inject the Velocity Engine in directly to the
config (just is done for the Templated Attribute Definition in both V2 and
V3).

In order to do this simply I would like to change dataconnector schema file
such that the (fixed) attribute 

<attribute name="templateEngine" type="string"
fixed="shibboleth.TemplateEngine">

For the data connectors to becomes

<attribute name="templateEngine" type="string"
fixed="shibboleth.VelocityEngine">

Just as it is for the TemplatedAttribute definition.

AIUI, the fact that in V2 we always had schema validation means that no one
was ever overriding the value and so changing it should be safe.  But I'd
like to just check in here before I do this.

Rod