macosx: Get rid of old VLCTableViewCommon
macosx: Add new playlist model

The current playlist model directly operates on the core playlist
datastructures without proper locking for a complete playlist table
reload/update. This resulted in various ugly hacks and workarounds.

The new playlist model encapsulates the data in own objects like
in the qt interface. This allows a much easier integration with
the table view and proper updates from the core playlist.

This way, the previous playlist objects, stored in an ugly map with
pointer strings as keys, pointing to the same pointer inside a
NSValue, is obsolete finally. :-)
macosx: Use core-provided playlist search functionality

This removes the old own-made search functionality and replaces
it by a version the user would expect (i.e. actually hiding non-
found entries).

close #6049
macosx: Move drag and drop support to new PLModel and rewrite

This simplifies the methods, also using a simpler storage for
dragged items.
macosx: simplify/unify addition of new playlist items
macosx: add new pl items to the end if they are dropped to a node
macosx: adapt recursiveExpandNode to new playlist model
macosx: playlist: delete old NSOutlineViewDataSource and helpers

This is superseeded by the new PLModel object. Also remove old
helper functions which are not used anymore.
auhal: fix memleak, check malloc return value
macosx: resume playback: fix memleak
macosx: remove old playlist data source, remove unneeded outline view inits