Pluggable annotations - proposal.
Merge branch 'features/pluggable_annotations' of github.com:tbak/ribbon into pluggable-annotations
Annotation processor WIP.
Merge branch 'master' of https://github.com/Netflix/ribbon into pluggable-annotations

Conflicts:
	ribbon/src/main/java/com/netflix/ribbon/http/HttpResourceGroup.java
	ribbon/src/main/java/com/netflix/ribbon/proxy/MethodTemplateExecutor.java

Move annotation processing to individual processor.
Fix Issue #156 and #149
Fix Issue #141
Make annotation processors provider DI friendly.
Removed unused classes
Changes according to code review comments.
Merge pull request #157 from allenxwang/pluggable-annotations

Fix Issue #156, #149 and #141