Move integration tests => src/test

This commit eliminates the 'integration-tests' subproject in favor of
managing these sources under the root project's own 'src' directory.

This helps to avoid special-case handling for integration-tests in the
Gradle build, e.g. avoiding publication of jars to Artifactory /
Maven Central.

It is also semantically more correct. This is not a Spring Framework
subproject so much as it is a collection of integration tests that
span functionality across many subprojects. In this way, it makes
sense to place them directly under the root project.

Issue: SPR-8116

src/test/resources/log4j.xml

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
+
+<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
+
+	<!-- Appenders -->
+	<appender name="console" class="org.apache.log4j.ConsoleAppender">
+		<param name="Target" value="System.out" />
+		<layout class="org.apache.log4j.PatternLayout">
+			<param name="ConversionPattern" value="%-5p: %c - %m%n" />
+		</layout>
+	</appender>
+
+	<logger name="org.springframework.beans">
+		<level value="warn" />
+	</logger>
+
+	<logger name="org.springframework.beans.factory.xml.XmlBeanFactory">
+		<level value="error" />
+	</logger>
+
+	<logger name="org.springframework.binding">
+		<level value="debug" />
+	</logger>
+
+	<!-- Root Logger -->
+	<root>
+		<priority value="warn" />
+		<appender-ref ref="console" />
+	</root>
+	
+</log4j:configuration>

src/test/resources/org/springframework/transaction/annotation/enable-caching.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xmlns:cache="http://www.springframework.org/schema/cache"
+	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
+		http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache.xsd">
+
+	<cache:annotation-driven/>
+
+</beans>

src/test/resources/org/springframework/util/testlog4j.properties

@@ -0,0 +1,2 @@
+log4j.rootCategory=DEBUG, mock
+log4j.appender.mock=org.springframework.util.MockLog4jAppender

src/test/resources/org/springframework/web/util/testlog4j.properties

@@ -0,0 +1,2 @@
+log4j.rootCategory=DEBUG, mock
+log4j.appender.mock=org.springframework.util.MockLog4jAppender

src/test/resources/testlog4j.properties

@@ -0,0 +1,2 @@
+log4j.rootCategory=DEBUG, mock
+log4j.appender.mock=org.springframework.util.MockLog4jAppender