[gexiv2] build: Enable maintainer mode and silent rules

[Jens Georg <jensgeorg src gnome org>]

commit 5f76c3307a02def72035e04ac7dfb9a8ee699c82
Author: Jens Georg <mail jensge org>
Date:   Sun Jul 17 12:45:04 2016 +0200

    build: Enable maintainer mode and silent rules
    
    Signed-off-by: Jens Georg <mail jensge org>

 configure.ac |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 3545252..da6e7a3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -6,6 +6,10 @@ AC_CONFIG_MACRO_DIR([m4])
 # Will install auxiliary build tools (depcomp, install-sh, missing...) under build-aux/
 AC_CONFIG_AUX_DIR([build-aux])
 AM_INIT_AUTOMAKE([1.11 -Wall no-define foreign dist-xz no-dist-gzip tar-ustar subdir-objects])
+
+AM_MAINTAINER_MODE([enable])
+AM_SILENT_RULES([yes])
+
 AM_PROG_AR
 LT_PREREQ([2.2])
 LT_INIT([disable-static win32-dll])