Add an annotation processor that generates properties files for certain
auto-configuration class annotations. Currently attribute values from
@AutoConfigureOrder, @AutoConfigureBefore, @AutoConfigureAfter and
@ConditionalOnClass annotations are stored.
The properties file will allow optimizations to be added in the
`spring-boot-autoconfigure` project. Primarily by removing the need
to ASM parse as many `.class` files.
See gh-7573
Phillip Webb
Madhura Bhave
Andy Wilkinson
Stephane Nicoll