Nice Ant 1.6.3 improvement for default values

Apache Ant 1.6.3 added a nice feature to the condition task. There is now an else attribute. The niceness is best illustrated by example:

<property environment="env"/>

<!-- The old, pre-1.6.3 way:-->
<condition property="foo.bar" value="${env.FOO_BAR}">
    <isset property="env.FOO_BAR"/>
</condition>
<condition property="foo.bar" value="Lives somewhere else">
    <not>
        <isset property="env.FOO_BAR"/>
    </not>
</condition>

And with Ant 1.6.3:

<property environment="env"/>

<!-- The new, 1.6.3 way:-->
<condition property="foo.bar" value="${env.FOO_BAR}"
        else="Lives somewhere else">
    <isset property="env.FOO_BAR"/>
</condition>

It could be more concise still, but this is an improvement.