This function is a copy of the get_cached function from
HttpCachingBridgeAbstract, adding all parameters of
getSimpleHTMLDOM in order to replace the need of
HttpCachingBridgeAbstract entirely
The files have grown to a size where it is necessary to search
for a class in a file. This commit splits the content into one
file per class. RSS-Bridge will require implementations and
the implementations will require (once) the interfaces.
