I finally found this link, discovered the issue to be double property declarations, both in my persistence.xml as well as in my applicationContext.xml. Once those were cleaned out and had my files looking:
applicationContext.xml:
<bean class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close" id="dataSource">
<property name="driverClassName" value="${database.driverClassName}"/>
<property name="url" value="${database.url}"/>
<property name="username" value="${database.username}"/>
<property name="password" value="${database.password}"/>
<property name="testOnBorrow" value="false"/>
<property name="testOnReturn" value="false"/>
<property name="testWhileIdle" value="false"/>
<property name="timeBetweenEvictionRunsMillis" value="1800000"/>
<property name="numTestsPerEvictionRun" value="3"/>
<property name="maxActive" value="1" />
<property name="minEvictableIdleTimeMillis" value="1800000"/>
</bean>
persistence.xml
<properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect" />
<property name="hibernate.hbm2ddl.auto" value="create"/>
</properties>
Everything ran just fine.