changed the pom so it will work with the last guava library
changed the log4j configuration file so only serious problems in the Reflections library will be shown (most logging messages coming from that library are just annoying)
Adding a class declaring the names of all the known supported logic engines
changing the PrologEngineConfiguration class so it includes methods for returning the logic engine name and the library name they use
changing most log messages from debug to trace in the class LogicEngineWriter
minor refactorings
adding a method to the Query class for returning all the solutions as a multi map
Added a class for pooling and managing many instances of PrologEngineConfiguration classes.