Cleaning up the plugin + header comments.

- Removing getAst (won't be used in practice)
- Renaming namedBasedRead for readAstFile (more understandable?)
- ...
Merge branch 'master' of https://github.com/aghosn/persistence

Conflicts:
	library/src/main/scala/reflect/persistence/ToolBox.scala
	library/src/test/scala/ToolBoxTest.scala
	plugin/src/main/scala/scala/reflect/persistence/Enrichments.scala