Add Atomikos support classes

Add support classes for the Atomikos JTA library, including:

- A Spring friendly ConnectionFactoryBean and DataSourceBean.
- A PostProcessor to apply "depends-on" ordering automatically.
- A bindable properties class for type-safe configuration.

See gh-947

spring-boot/pom.xml

@@ -34,11 +34,31 @@
 			<artifactId>logback-classic</artifactId>
 			<optional>true</optional>
 		</dependency>
+		<dependency>
+			<groupId>com.atomikos</groupId>
+			<artifactId>transactions-jms</artifactId>
+			<optional>true</optional>
+		</dependency>
+		<dependency>
+			<groupId>com.atomikos</groupId>
+			<artifactId>transactions-jta</artifactId>
+			<optional>true</optional>
+		</dependency>
+		<dependency>
+			<groupId>com.atomikos</groupId>
+			<artifactId>transactions-jdbc</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>com.fasterxml.jackson.core</groupId>
 			<artifactId>jackson-databind</artifactId>
 			<optional>true</optional>
 		</dependency>
+		<dependency>
+			<groupId>javax.jms</groupId>
+			<artifactId>jms-api</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>javax.servlet</groupId>
 			<artifactId>javax.servlet-api</artifactId>