Remove superfluous starter dependencies

Remove superfluous dependencies from spring-boot-starter-tomcat and
spring-boot-starter-jetty which caused gradle based builds to put
too many libraries in `/lib-provided` when building a war.

Fixes gh-1064

spring-boot-starters/spring-boot-starter-jetty/pom.xml

@@ -18,10 +18,6 @@
 		<main.basedir>${basedir}/../..</main.basedir>
 	</properties>
 	<dependencies>
-		<dependency>
-			<groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-starter</artifactId>
-		</dependency>
 		<dependency>
 			<groupId>org.eclipse.jetty</groupId>
 			<artifactId>jetty-webapp</artifactId>
@@ -30,15 +26,5 @@
 			<groupId>org.eclipse.jetty</groupId>
 			<artifactId>jetty-jsp</artifactId>
 		</dependency>
-		<dependency>
-			<groupId>org.springframework</groupId>
-			<artifactId>spring-core</artifactId>
-			<exclusions>
-				<exclusion>
-					<groupId>commons-logging</groupId>
-					<artifactId>commons-logging</artifactId>
-				</exclusion>
-			</exclusions>
-		</dependency>
 	</dependencies>
 </project>

spring-boot-starters/spring-boot-starter-tomcat/pom.xml

@@ -18,10 +18,6 @@
 		<main.basedir>${basedir}/../..</main.basedir>
 	</properties>
 	<dependencies>
-		<dependency>
-			<groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-starter</artifactId>
-		</dependency>
 		<dependency>
 			<groupId>org.apache.tomcat.embed</groupId>
 			<artifactId>tomcat-embed-core</artifactId>
@@ -34,15 +30,5 @@
 			<groupId>org.apache.tomcat.embed</groupId>
 			<artifactId>tomcat-embed-logging-juli</artifactId>
 		</dependency>
-		<dependency>
-			<groupId>org.springframework</groupId>
-			<artifactId>spring-core</artifactId>
-			<exclusions>
-				<exclusion>
-					<groupId>commons-logging</groupId>
-					<artifactId>commons-logging</artifactId>
-				</exclusion>
-			</exclusions>
-		</dependency>
 	</dependencies>
 </project>