Error out if an extra pak can not be found
Make modelist print to regular log not developer. Remove extra newlines
Remove unused variable
When the areaportalMask changes invalidate all cached clusters.

Invalidating only the current view cluster is not enough, because the
player can walk back into an already cached cluster which then would
be drawn based on the old areamask setting.
Merge branch 'master' into for-0.26
Merge branch 'for-0.26' into librocket