Move TimestampsIO and Varint classes to an "io" package
Split TimestampsIO into TimestampsReader and TimestampsWriter classes
Remove @since tags from Javadoc
Mark classes as "final"
Move console log parsing out of TimestampsReader.find, into a new class
Make TimestamperOutputStream a top-level class

In order to improve the unit test, TimestamperWriter is now an interface.
Move readAllTimestamps methods into TimestampsIOTest
Define NEWLINE variable in unit tests instead of 0x0A