Set target compatibility flag
Move delimited text rating cursor into data.text package
Add `@since` annotations to text parameters
Use Grapht dev version with aliases
Move user and file DAO providers to `.text`.
Introduce LineCursor
Add Plus event (#517)

- Plus event interface
- SimplePlus implementation and factories
- Tests for the factories
Add EventBuilder abstraction
Add UnaryEventBuilder abstraction for unary events
Add PlusBuilder and a test class
Add Factory interface and utility class
Add multiPlus factory method
Add plus count summarize
Generalized parsing of events from text files

- TextEventDAO parses events from text line-by-line
- EventFormat describes how to parse an event from a line
- Use this to parse ratings
Add missing license headers
Simplify and reuse code for rating parse contexts
Move user and item DAO tests to .text
Use field lists to parse ratings
Simplify event builder hierarchy
Add event type definition