exiv2: new package

Add support for Exiv2 library and utility to manage image metadata

Exiv2 can be built in GPLv2+ or commercial version. But in commercial
version the Nikon lens name database and the NLS support has to be
disabled for copyright reason.

[Thomas:
 - switch to using the CMake build system, which works better than the
   clunky autoconf + manual Makefile based build system.
 - add missing toolchains dependencies: does not build in static
   library configuration, needs C++, etc.]

Signed-off-by: Nicolas Serafini <nicolas.serafini@sensefly.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
diff --git a/package/Config.in b/package/Config.in
index a6977ce..e91e95b 100644
--- a/package/Config.in
+++ b/package/Config.in
@@ -632,6 +632,7 @@
 	source "package/adwaita-icon-theme/Config.in"
 	source "package/atk/Config.in"
 	source "package/cairo/Config.in"
+	source "package/exiv2/Config.in"
 	source "package/fltk/Config.in"
 	source "package/fontconfig/Config.in"
 	source "package/freetype/Config.in"