Adding start/end as static Position

Add the streamPosition constants
Move Projections into the expose classes section
Version 0.2.2

src/client.js

@@ -4,15 +4,23 @@ var results = require('./results');
 const expectedVersion = {
   any: -2,
   noStream: -1,
-  emptyStream: -1
+  emptyStream: -1,
+  streamExists: -4
 };
 Object.freeze(expectedVersion);
+
 const positions = {
   start: new results.Position(0, 0),
   end: new results.Position(-1, -1)
 };
 Object.freeze(positions);
 
+const streamPosition = {
+  start: 0,
+  end: -1
+};
+Object.freeze(streamPosition);
+
 /**
  * Create an EventData object from JavaScript event/metadata that will be serialized as json
  * @public
@@ -60,6 +68,7 @@ module.exports.ProjectionCommandFailedError = require('./errors/projectionComman
 // Expose enums/constants
 module.exports.expectedVersion = expectedVersion;
 module.exports.positions = positions;
+module.exports.streamPosition = streamPosition;
 module.exports.systemMetadata = require('./common/systemMetadata');
 module.exports.eventReadStatus = results.EventReadStatus;
 module.exports.sliceReadStatus = require('./sliceReadStatus');

src/results.js

@@ -30,6 +30,8 @@ Position.prototype.toString = function() {
   return [this.commitPosition.toString(), this.preparePosition.toString()].join("/");
 };
 
+Position.start = new Position(0,0);
+Position.end = new Position(-1,-1);
 
 const EventReadStatus = {
   Success: 'success',