Agent changes for measuring multiple steps (renamed result files)

Conflicts:
	agent/wpthook/results.cc
	agent/wpthook/results.h

Conflicts:
	agent/wpthook/results.cc
Added "cleanup-batch" option for browser settings in "wptdriver.ini".
The batch is executed after the browser should have been closed (e.g. the script can be used to close browser if it is still running)

Conflicts:
	agent/wptdriver/web_browser.cc
	agent/wptdriver/wpt_settings.cc
	agent/wptdriver/wpt_settings.h
Extended server for test scripts which measure multiple steps

Conflicts:
	www/webpagetest/breakdown.inc
	www/webpagetest/breakdown.php
	www/webpagetest/customWaterfall.php
	www/webpagetest/details.php
	www/webpagetest/domains.inc
	www/webpagetest/domains.php
	www/webpagetest/export.php
	www/webpagetest/object_detail.inc
	www/webpagetest/optimization.inc
	www/webpagetest/optimizationChecklist.php
	www/webpagetest/page_data.inc
	www/webpagetest/pageimages.php
	www/webpagetest/performance_optimization.php
	www/webpagetest/result.inc
	www/webpagetest/results.php
	www/webpagetest/screen_shot.php
	www/webpagetest/thumbnail.php
	www/webpagetest/utils.inc
	www/webpagetest/video/compare.php
	www/webpagetest/waterfall.css
	www/webpagetest/waterfall.inc
	www/webpagetest/waterfall.js
	www/webpagetest/waterfall.php
	www/webpagetest/waterfall_detail.inc
	www/webpagetest/work/workdone.php
	www/webpagetest/xmlResult.php