Improved binding algorithm for nuun-spring-plugin

Application context hierarchy is now completely scanned for candidate beans before actually binding them. A getMergedBeanDefinition() call is used to account for parent beans. Bean override handling is (too) basic, taking only into account the first bean encoutered and ignoring the others that may exist upper in the hierarchy.

The flags for controlling binding types (byName, byType, byParent) were removed as the current analysis algorithm is (seems to be) working in all cases.

The byParent binding portion of the test has been removed.