Fix dependency setup.

Unify test dependencies in parent pom.xml. Fixed logging dependencies to only depend on SLF4j API now (in version 1.7.1). Using Logback as test runtime loggin dependency. Fixed Hamcrest/JUnit setup.

core/pom.xml

@@ -18,7 +18,14 @@
 			<groupId>org.springframework</groupId>
 			<artifactId>spring-beans</artifactId>
 			<version>${spring.version}</version>
+			<exclusions>
+				<exclusion>
+					<groupId>commons-logging</groupId>
+					<artifactId>commons-logging</artifactId>
+				</exclusion>
+			</exclusions>
 		</dependency>
+		
 		<dependency>
 			<groupId>org.springframework</groupId>
 			<artifactId>spring-context</artifactId>