Add spring.messages.cacheSeconds to global config

Fixes gh-625

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/MessageSourceAutoConfiguration.java

@@ -58,6 +58,8 @@ public class MessageSourceAutoConfiguration implements EnvironmentAware {
 		}
 		String encoding = this.environment.getProperty("encoding", "utf-8");
 		messageSource.setDefaultEncoding(encoding);
+		messageSource.setCacheSeconds(this.environment.getProperty("cacheSeconds",
+				Integer.class, -1));
 		return messageSource;
 	}
 

spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc

@@ -81,6 +81,7 @@ content into your application; rather pick only the properties that you need.
 	# INTERNATIONALIZATION ({sc-spring-boot-autoconfigure}/MessageSourceAutoConfiguration.{sc-ext}[MessageSourceAutoConfiguration])
 	spring.messages.basename=messages
 	spring.messages.encoding=UTF-8
+    spring.messages.cacheSeconds=-1
 
 	[[common-application-properties-security]]
 	# SECURITY ({sc-spring-boot-autoconfigure}/security/SecurityProperties.{sc-ext}[SecurityProperties])