Update UPGRADE.md
Abstract Kernel implements SuluKernel
updated translations

Conflicts:
	web/admin/translations/sulu.de.json
	web/admin/translations/sulu.en.json
added widgets to config.yml
moved widgets config to admin
updated dependencies
added reverse-proxy ttl handling
Merge branch 'feature/reverse-proxy-ttl' into develop
updated dependencies
corrected webspace config
Merge pull request #261 from sulu-cmf/feature/sulu-kernel

[ENHANCEMENT] Abstract Kernel implements SuluKernel
updated dependencies
Updated name of navigation function in client template
Merge pull request #284 from sulu-cmf/hotfix/navigation_fix

Updated name of navigation function in client template
Merge branch 'develop' of github.com:sulu-cmf/sulu-standard into develop
updated dependencies
enalbe request analyzer for admin