ArrayImplementation uses unsetted(nulled) paths
The ArrayImplementation tries to render non existing paths when an path is unset with ">".
The Reason is, that the TypoScript Parser doesn't remove the path, instead it sets it to NULL.
As a quick fix i changed the ArrayImplementation to check if the path is null to skip it.
But in general this should be properly handled by the Parser.
[BUGFIX] Add a check for unsetted Paths in Arrays
When a path is unset it isn't really unset by the TypoScript
Parser, instead it's set to NULL. This can throw an error
of non existing paths that TypoScript tries to render.
As a temporary Fix this changeset adds a check if the
path is NULL to skip it.