added some missing error handling

services/track-changes/app/coffee/DocArchiveManager.coffee

@@ -26,12 +26,15 @@ module.exports = DocArchiveManager =
 
 	archiveDocChanges: (project_id, doc_id, callback)->
 		MongoManager.getDocChangesCount doc_id, (error, count) ->
+			return callback(error) if error?
 			if count == 0
 				return callback()
 			else
 				MongoManager.getLastCompressedUpdate doc_id, (error, update) ->
+					return callback(error) if error?
 					MongoAWS.archiveDocHistory project_id, doc_id, (error) ->
-						logger.log doc_id:doc_id, error: error, "export to S3"
+						return callback(error) if error?
+						logger.log doc_id:doc_id, project_id:project_id, "exported document to S3"
 						MongoManager.markDocHistoryAsArchived doc_id, update, (error) ->
 							return callback(error) if error?
 							callback()
@@ -48,11 +51,13 @@ module.exports = DocArchiveManager =
 
 	unArchiveDocChanges: (project_id, doc_id, callback)->
 		MongoManager.getArchivedDocChanges doc_id, (error, count) ->
+			return callback(error) if error?
 			if count == 0
 				return callback()
 			else
 				MongoAWS.unArchiveDocHistory project_id, doc_id, (error) ->
-					logger.log doc_id:doc_id, error: error, "import from S3"
+					return callback(error) if error?
+					logger.log doc_id:doc_id, project_id:project_id, "imported document from S3"
 					MongoManager.markDocHistoryAsUnarchived doc_id, (error) ->
 						return callback(error) if error?
 						callback()