[Bug-apl] AF_UNIX (aka AF_LOCAL) sockets

[Juergen Sauermann]

Hi,

Following an earlier proposal from Elias, I have changed from TCP sockets to
AF_UNIX sockets for the communication between apl and APserver if the
platform supports it (linux does). See SVN 368.

The long-term goal is to get rid of the APnnn processes that are forked with every
apl invocation and move their functionality to APserver.

This will take a while, though, so the next release will most likely come
before this move is finished completely.

/// Jürgen