Enable and fix warnings from automake.

configure.ac

@@ -4,7 +4,7 @@ AC_PREREQ(2.61)
 AC_INIT([tinc], [1.1pre7])
 AC_CONFIG_SRCDIR([src/tincd.c])
 AC_GNU_SOURCE
-AM_INIT_AUTOMAKE([check-news dist-bzip2 std-options subdir-objects])
+AM_INIT_AUTOMAKE([check-news dist-xz no-dist-gzip std-options subdir-objects -Wall])
 AC_CONFIG_HEADERS([config.h])
 AM_MAINTAINER_MODE
 
@@ -21,6 +21,8 @@ AC_PROG_INSTALL
 AC_PROG_LN_S
 AC_PROG_RANLIB
 
+AM_PROG_CC_C_O
+
 dnl Check and set OS
 
 AC_CANONICAL_HOST
@@ -211,8 +213,6 @@ AC_ARG_ENABLE(jumbograms,
   ]
 )
 
-AC_SUBST(INCLUDES)
-
 AC_CONFIG_FILES([Makefile src/Makefile doc/Makefile m4/Makefile gui/Makefile])
 
 AC_OUTPUT

src/Makefile.am

@@ -99,10 +99,6 @@ endif
 
 tinc_LDADD = $(READLINE_LIBS) $(CURSES_LIBS)
 
-DEFAULT_INCLUDES =
-
-INCLUDES = @INCLUDES@
-
 noinst_HEADERS = \
 	xalloc.h utils.h getopt.h list.h splay_tree.h dropin.h fake-getaddrinfo.h fake-getnameinfo.h fake-gai-errnos.h ipv6.h ipv4.h ethernet.h \
 	buffer.h conf.h connection.h control.h control_common.h device.h edge.h graph.h info.h logger.h meta.h net.h netutl.h node.h process.h \