Returns a stream of changes to a leveldb database.

Usage

var db = level('foo');
var c = changes(db, [opts]);
c.on('data', function(change) {
  console.log("Change:", change)
})

The change objects emitted have the properties:

{
  type: 'put', // or 'del'
  key: <key>,
  value: <value> // only present if type is 'put'
}

opts:

{
  gte: <start_key>, // range start
  lte: <end_key>,  // range end
  history: true, // stream output a 'put' change for each row already in db
}