Fixes #399 - Disable javadoc lint when building with Java 8

http://mail-archives.apache.org/mod_mbox/maven-users/201403.mbox/%3CCANWgJS5xHWiGE+Lecey+mZVbj9Via4JUWsaBeZtQr2aQNebupA@mail.gmail.com%3E
http://blog.joda.org/2014/02/turning-off-doclint-in-jdk-8-javadoc.html