change Kwf_Config::getValueArray to not cause error if parent setting doesn't exist, like getValue does
refactor view renderer and move plugins out of <kwc placeholder

It is not neccessary to add plugins to <kwc placeholders as they are the same for all. Instead they are now in the cached contents
allow running tests without memcache or apc
use plugins only when rendering type=component
allow partials to dynamically disable view cache

using that we can include the first page in the fullPage cache which greatly improves performance for the most common case