Ext dir now used in payloads, subsequent JNDI refactoring. Fixes #79

Now also with a warning if using singleton on non-system resource
Added printservice to common providers.
test fix: permgen was not correctly specified in pom.xml
test fix: slow VM could fail to wait long enough
tests now use a custom (empty) Maven settings.xml
Added possibility to use alternate maven settings.xml

by using parameter mavenSettingsFile
APIs now part of ext. Fixes #84