Maven projects fixes and improvements

* Fixed copy of the SQL files to the distribution

* Distribution packages will now execute an automatic clean-up before
assembling. While this will avoid having dirty, old files in the
distribution directory, it also has a negative consequence -
configuration files will be destroyed if they exist.

legacyworlds/pom.xml

@@ -53,6 +53,12 @@
 					<artifactId>tomcat-maven-plugin</artifactId>
 					<version>1.1</version>
 				</plugin>
+				
+				<plugin>
+					<groupId>org.apache.maven.plugins</groupId>
+					<artifactId>maven-clean-plugin</artifactId>
+					<version>2.4.1</version>
+				</plugin>
 
 			</plugins>
 		</pluginManagement>