fix #288 pdf preview fix ghostscript configuration
make ghostscript path configurate able
updated dependencies
updated composer
corrected composer version
Merge branch 'master' into hotfix/288
corrected merge
Merge branch 'hotfix/288' into develop

Conflicts:
	composer.json
	composer.lock
Merge branch 'develop' of github.com:sulu-cmf/sulu-standard into develop

Conflicts:
	composer.lock