resolved FindBugs violations: for non-transient, non-serializable instance field tracker, and serialVersionUID warning in CustomPollingImporterListServlet
Merge pull request #236 from adamcin/defect/custom-importers/findbugs-violation-non-transient-non-serializable-instance-field

Resolved FindBugs violations in CustomPollingImporterListServlet
added slf4j-api to the PMD plugin dependencies to trick the MoreThanOneLoggerRule into ignoring multiple SLF4j loggers
added a @SuppressWarnings("PMD.MoreThanOneLogger") annotation to JsonEventLogger to more properly address the fact that we specifically want more than one logger.
updating various plugins
Merge branch 'master' of github.com:Adobe-Consulting-Services/acs-aem-commons
#findbugs
#checkstyle
Merge pull request #237 from adamcin/defect/parent/pmd-maven-3.0.5-compatibility

Resolved PMD Violation: MoreThanOneLogger