Merge pull request #17 from davidmsantos90/core-refactor

[CDE-197]: fixed OlapSelector Component not working in Pentaho 4.x
created IPersistenceEngine and ISimplePersistence interfaces as per release-5 / 5-trunk branches; updated PersistenceEngine and SimplePersistence classes accordingly
[CLEANUP] as per comments left in https://github.com/webdetails/cpf/commit/a010a1a91c25eaa3ea4e6a5130c16e649f2d0792
- updated year in license headers
- cleaned author comments
- updated license header in SimplePersistence.java
Merge pull request #18 from pedrofvteixeira/core-refactor

[CLEANUP] as per comments left in https://github.com/webdetails/cpf/comm...
[CLEANUP] updated license headers; removed @author comment
added loadAll() method declaration to ISimplePersistence interface; method has already been implemented in SimplePersistence class
Merge pull request #19 from pedrofvteixeira/core-refactor

[CLEANUP] updated license headers; removed @author comment