Automate LazyCat installation with autotools.

* Makefile.am: Improve.
* Makefile.in: Update.
* server/server.c, server/scm/config.scm, server/scm/diff.scm,
  server/scm/host-list.scm, server/scm/host.scm,
  server/scm/lazycatd.scm, server/scm/logger.scm,
  server/scm/main.scm, server/scm/protocol.scm,
  ui/gtk/lazy-gtk-cat.scm: Remove "scm" from a module path.  All
  dependent modules updated.
* ui/lc: Rename to ui/lc.scm.
* ui/lazycat-gtk: Rename to ui/lazycat-gtk.scm.