FYI, ResourceResolver.close() can be called multiple times

[Bertrand Delacretaz]

Hi,

I have clarified that in the javadocs in
http://svn.apache.org/r1479508 - it was already tested by
ResourceResolverImplTest.testClose but not 100% clear from the
javadocs.

IOW, no need to do

if(resolver.isLive()) {
  resolver.close()
}

-Bertrand