Support property expansion in redirect-port attribute of the web system's connector

The connector element of the web subsystem doesn't support property expansion, forcing you to hardwire the port
number. E.g., writing:
...
<subsystem xmlns="urn:jboss:domain:web:1.1" default-virtual-server="default-host">
<connector name="http" protocol="HTTP/1.1" scheme="http" socket-binding="http"
redirect-port="${jboss.web.https.port}"/>
...
causes a NumberFormatException. Runtime properties for this attribute was supported in previous versions.
Another problem is that there is no predefined property with the above name.

An alternative solution is to allow a reference to a socket binding groups in the attribute value, as discussed in
http://community.jboss.org/thread/176339