Configurable in-memory cache for playing media

A configurable, transparent buffer for the media being currently played would enable disks to be spun down during playback, as well as allowing latent connections be used without interruption.

The end user would allocate an amount (e.g. 500mb) of maximum memory to be used, and an appropriate amount of media would be pre-loaded into it. Even for relatively small allocated amounts, disks would be allowed to spin down for extended periods of time during playback.

For most use cases (media centre, laptop) this is very desirable and power saving behaviour, and would be a welcome addition.

added Component::Core Difficulty::hard Severity::normal Type::feature Version::master git + 1 deleted label

changed milestone to %Features paradize

added Component::Core: Input label and removed Component::Core label

The in-memory cache is implemented in c74fb8e1.

It's not enabled for local media because it could cause an I/O storm, and seriously damage responsiveness of the whole system. Also it does not save power unless the cache is larger than the media; in other cases, I/O will keep going to refill the cache.

unassigned @Courmisch