Added support for envers and annotation configuration

I propose adding envers support and AnnotationConfiguration support. Envers and annotation strategy could be configured in user's pom.xml as:


			<plugin>
				<groupId>de.akquinet.maven</groupId>
				<artifactId>hibernate4-maven-plugin</artifactId>
				<version>0.3-SNAPSHOT</version>
                <configuration>
                    <configurationStrategy>ANNOTATION</configurationStrategy>
                </configuration>
				<dependencies>
					<dependency>
						<groupId>org.hibernate</groupId>
						<artifactId>hibernate-core</artifactId>
						<version>${hibernate.version}</version>
					</dependency>
					<dependency>
						<groupId>org.hibernate</groupId>
						<artifactId>hibernate-envers</artifactId>
						<version>${hibernate.version}</version>
					</dependency>
				</dependencies>
			</plugin>

Envers dependency is optional.