Fix request #7218 Building autoload takes 20 minutes

I create an autoload-dev that generate only autoload for modified plugins and sections.

For instance, with the following git status:

 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
   (use "git checkout -- <file>..." to discard changes in working directory)

	modified:   Makefile
	modified:   plugins/fulltextsearch/include/SystemEvent_FULLTEXTSEARCH_WIKI_INDEX.class.php
	modified:   plugins/fulltextsearch/tests/SystemEvent_FULLTEXTSEARCH_WIKITest.class.php
	modified:   plugins/mediawiki/tests/bootstrap.php

 Untracked files:
   (use "git add <file>..." to include in what will be committed)

	tools/utils/autoload.sh

> make autoload-dev will only generate fulltextsearch autoload file.

Change-Id: Ic1250b90bdb8d6b4623a14a02a2304ac08514b0c
Merge commit 'refs/changes/68/2768/1' of ssh://gerrit.tuleap.net:29418/tuleap into stable

* ssh://gerrit.tuleap.net:29418/tuleap:
  Fix request #7218 Building autoload takes 20 minutes
This is Tuleap 7.2.99.51

Change-Id: If455017856b2089a2b924b7a5361e0625160b54f