awget/awgetd.scm: Turn to a standalone program.

Turn the awgetd to a standalone program.  This is the first step
to make awget work over a network.

* awget/awgetd.scm: Rename to `awget/awgetd.in'.  Turn to a
  standalone program.
* awget/awget.in (print-help-and-exit): Update.
  (daemonize): Remove.
  (main): Remove most of the stuff related to awgetd.
* awget/Makefile.am (bin_SCRIPTS): Add `awgetd'.
  (awget_DATA): Remove `awgetd.scm'.
  (awgetd): New target.