... or couldn't hurt anyway.
1. Extends the definition of a web application for @ConditionalOnWebapp
so that a StandardEnvironment can be used (cutting out JNDI failures
for Environment properties)
2. Doesn't bother using StandardServletEnvironment in integration tests
3. Make the NON_ENUMERABLE_ENUMERABLES in PropertySourcesPropertyValues
static so they only get initialized once (not a huge issue at all)