logic: Improvements in indexing to avoid OOM (issue #471)

* indexer processes wait if already too many storages queued
* storage fetcher waits if already too many storages queued
* increased size estimation for shared memory of indexer commands
* Added MessageFilterNewErrors to combine messages for new errors

bug id = 471

setup/Linux/Sourcetrail.sh

@@ -1,5 +1,3 @@
-#!/bin/sh
-
 # get the current directory
 SOURCE="${0}"
 while [ -h "$SOURCE" ]; do # resolve $SOURCE until the file is no longer a symlink