pom.xml(slf4j): updated to 1.7.9

@see http://www.slf4j.org/news.html

Also enabled new slf4j.detectLoggerNameMismatch option and fixed appropriate warnings.

No functional changes.

fix
pom.xml(h2): updated to 1.4.184

@see http://www.h2database.com/html/changelog.html

No functional changes.
pom.xml(maven-pmd-plugin): updated to 3.3

This also updates PMD to 5.2.1

@see http://mail-archives.apache.org/mod_mbox/maven-users/201411.mbox/%3CCAK8jvqxjF0BLY7WGcbdnm8sOmXxSc-=y3RmxcuaNGZTHPDT84Q@mail.gmail.com%3E
@see http://pmd.sourceforge.net/pmd-5.1.3/changelog.html
@see http://pmd.sourceforge.net/pmd-5.2.0/overview/changelog.html
@see http://pmd.sourceforge.net/pmd-5.2.1/overview/changelog.html

No functional changes.