The current `resource-root` path can either be absolute or relative. We have found a scenario where we'd like to provide an environment variable as part of the path.

The extension we'd like to propose is to support the following resource-root path:

<resource-root path="${ENV_PROP}/some/path"> or <resource-root path="${SYS_PROP}/some/path">.

in addition to the absolute and relative path resolution.