Removes divs to avoid margin problems
Fixes Package::getDependentPackages()

Also optimizes Package:: getRequiredPackages()
Removes unused method Package::getDependencies()
Using latest version of com.woltlab.wcf.acp.style
Merge branch 'master' of github.com:WoltLab/WCF
Fixed landing page after package (un-)installation

Fixes #1070
Ignoring optionals if already installed

Fixes #1065
Hide style chooser unless two or more styles are given

Fixes #895