Add human-readable URLs for collections' pages.

Fix GH #67
pom.xml(maven-checkstyle-plugin): updated to 2.13

@see http://mail-archives.apache.org/mod_mbox/maven-users/201409.mbox/%3C1430082.PcumKFdX1o@herve-desktop%3E

No functional changes.
pom.xml(maven-pmd-plugin): updated to 3.2

This also updates PMD to 5.1.2

@see http://mail-archives.apache.org/mod_mbox/maven-announce/201408.mbox/%3C312099282.01406985547654.JavaMail.Dennis@Dennis-Dator%3E
@see http://pmd.sourceforge.net/pmd-5.1.0/changelog.html
@see http://pmd.sourceforge.net/pmd-5.1.1/changelog.html
@see http://pmd.sourceforge.net/pmd-5.1.2/changelog.html

No functional changes.