Added a new resetBeanIntrospectors() method.

This method completes BEANUTILS-425 by a means to reset introspection to its
initial state. The test case for PropertyUtils has been made more robust
against potential failures caused by randomized execution order.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/beanutils/trunk@1547898 13f79535-47bb-0310-9956-ffa450edef68
Updated release version and generated a new download page.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/beanutils/trunk@1547899 13f79535-47bb-0310-9956-ffa450edef68
Adapted build.xml.

Aligned the ant build with the maven build. Build is now successful with ant.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/beanutils/trunk@1547900 13f79535-47bb-0310-9956-ffa450edef68