Fix property names with successive capital letters

Previously, if a property name had successive capital letters, the
generated meta-data would clean it in such a way it is defined as a
regular word. For instance a `myFOO` property would be written as
`my-foo` in the meta-data.

It turns out this decision is wrong as the binder has no way to compute
back the name of the property and therefore `my-foo` wouldn't bind to
`setMyFOO` as it should.

This commit updates the meta-data name generation algorithm to properly
identify such cases: `myFOO` now translates to `my-f-o-o`. While the
generated name is a bit ugly, it now provides a consistent binding
experience.

Closes gh-5330

spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationprocessor/metadata/ConfigurationMetadataTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2014 the original author or authors.
+ * Copyright 2012-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -33,35 +33,45 @@ public class ConfigurationMetadataTests {
 		assertThat(toDashedCase("simpleCamelCase"), is("simple-camel-case"));
 	}
 
+	@Test
+	public void toDashedCaseUpperCamelCaseSuffix() {
+		assertThat(toDashedCase("myDLQ"), is("my-d-l-q"));
+	}
+
+	@Test
+	public void toDashedCaseUpperCamelCaseMiddle() {
+		assertThat(toDashedCase("someDLQKey"), is("some-d-l-q-key"));
+	}
+
 	@Test
 	public void toDashedCaseWordsUnderscore() {
-		assertThat(toDashedCase("Word_With_underscore"), is("word_with_underscore"));
+		assertThat(toDashedCase("Word_With_underscore"), is("word-with-underscore"));
 	}
 
 	@Test
 	public void toDashedCaseWordsSeveralUnderscores() {
 		assertThat(toDashedCase("Word___With__underscore"),
-				is("word___with__underscore"));
+				is("word---with--underscore"));
 	}
 
 	@Test
 	public void toDashedCaseLowerCaseUnderscore() {
-		assertThat(toDashedCase("lower_underscore"), is("lower_underscore"));
+		assertThat(toDashedCase("lower_underscore"), is("lower-underscore"));
 	}
 
 	@Test
-	public void toDashedCaseUpperUnderscore() {
-		assertThat(toDashedCase("UPPER_UNDERSCORE"), is("upper_underscore"));
+	public void toDashedCaseUpperUnderscoreSuffix() {
+		assertThat(toDashedCase("my_DLQ"), is("my-d-l-q"));
+	}
+
+	@Test
+	public void toDashedCaseUpperUnderscoreMiddle() {
+		assertThat(toDashedCase("some_DLQ_key"), is("some-d-l-q-key"));
 	}
 
 	@Test
 	public void toDashedCaseMultipleUnderscores() {
-		assertThat(toDashedCase("super___crazy"), is("super___crazy"));
-	}
-
-	@Test
-	public void toDashedCaseUppercase() {
-		assertThat(toDashedCase("UPPERCASE"), is("uppercase"));
+		assertThat(toDashedCase("super___crazy"), is("super---crazy"));
 	}
 
 	@Test