Replace 'springsource.org' with 'spring.io'

Replace all references to 'springsource.org' with the new 'spring.io'
domain.
#58 - Upgraded Spring Data JPA dependencies to Babbage release train.

Adapted to changes in the API in Spring Data Commons which requires to pass in the current Environment into the AnnotationRepositoryConfigurationSource.
Add PropertiesLauncher
Add some tests for PropertiesLauncher
Loader changes
Re-organize the Launcher code a bit
Add internal property replacement

E.g. in application.properties (for launcher)

foo: Application
loader.main: my.${foo}
loader.path: etc
Add loader.system (flag to copy properties to System)
Further re-organization of launcher code
Polish whitespace