change mongomangers upsert to use an inc

this is tested and does work with new documents

services/docstore/app/coffee/MongoManager.coffee

@@ -12,9 +12,10 @@ module.exports = MongoManager =
 	upsertIntoDocCollection: (project_id, doc_id, lines, oldRev, callback)->
 		update =
 			$set:{}
+			$inc:{}
 		update.$set["lines"] = lines
 		update.$set["project_id"] = ObjectId(project_id)
-		update.$set["rev"] = oldRev + 1
+		update.$inc["rev"] = 1 #on new docs being created this will set the rev to 1
 		db.docs.update _id: ObjectId(doc_id), update, {upsert: true}, callback
 
 

services/docstore/test/unit/coffee/MongoManagerTests.coffee

@@ -61,7 +61,7 @@ describe "MongoManager", ->
 				args = @db.docs.update.args[0]
 				assert.deepEqual args[0], {_id: ObjectId(@doc_id)}
 				assert.equal args[1]["$set"]["lines"], @lines
-				assert.equal args[1]["$set"]["rev"], 78
+				assert.equal args[1]["$inc"]["rev"], 1
 				assert.deepEqual args[1]["$set"]["project_id"], ObjectId(@project_id)
 				done()