Add transformation from legacy items to FeedItems, before transforming
items to the desired format. This allows using legacy bridges alongside
bridges that return FeedItems.
As discussed in #940, instead of throwing exceptions on invalid
parameters, add messages to the debug log instead
Add support for strings to setTimestamp(). If the provided timestamp
is a string, automatically try to parse it using strtotime().
This allows bridges to simply use `$item['timestamp'] = $timestamp;`
instead of `$item['timestamp'] = strtotime($timestamp);`
Support simple_html_dom_node as input paramter for setURI
Support simple_html_dom_node as input parameter for setContent
getDatas -> getItems
setDatas -> setItems
Note: Bridge->setDatas actually sets data, where Bridge->getItems
only returns items (this is why Bridge->setDatas was not changed)
