Added inlinedConfScript property #2797

[JustinKSU]

Added inlinedConfScript which can reference a file path or a File
object. This property can be used to add additional commands (e.g.
setting JAVA_OPTS) to the default launcher script.

Utilizes FileCopyUtils now. Added missing JavaDoc.

Feature requested in #2797

[JustinKSU]

Need to fix the unit test. inlinedConfScriptCanBeReplaced() can be removed because it's covered by inlinedConfScriptFileLoad

[JustinKSU]

Latest error is unrelated to changes in this pull request:
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project spring-boot-autoconfigure: Compilation failure
[ERROR] /home/travis/build/spring-projects/spring-boot/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/AbstractRepositoryConfigurationSourceSupport.java:[67,24] constructor AnnotationRepositoryConfigurationSource in class org.springframework.data.repository.config.AnnotationRepositoryConfigurationSource cannot be applied to given types;

[wilkinsona]

@JustinKSU Yep, don't worry about that. It should have been fixed by 5a4ef50.

[wilkinsona]

Thanks for the PR. I've merged the changes into master. I polished things a little bit, most notably reverting the move to FileCopyUtils. While not necessarily a bad thing to do, I'd prefer to keep the changes focussed on adding the inlined conf script support.