Increase player state persisting buffer time.
Don't persist track information for TuneIn stations. They will be
updated upon the next track change anyway.
Bug 17998
Force description/title/changes to an empty string if there's no valid
value. We would end up in a hash pointer otherwise.
Fix search path configuration for plugins.

Plugins providing binary modules would sometimes fail to load. We need
to apply to same path handling as we do in bootstrap.pm to make sure
we'll find platform specific binary modules.
Prevent parallel lookups of the same data.

Set the fetchingMeta flag asap to prevent multiple parallel lookups of
the same data. If that flag is not set, calls for all the tracks in a
playlist could trigger the full request for each of them, as the flag is
only set once the first request has handled all tracks in the playlist.
Bump upper slider limit for play/startup delays. Some users need larger
values under certain circumstances.
Merge branch 'public/7.7' into public/10.0

Change-Id: Id93c30440e4f8af6cc6332939746bba0b216cb2a