Update to latest Appstream spec

Thanks to Michael Biebl for the heads up

configure.ac

@@ -1,5 +1,5 @@
 dnl Set package name and maintainer
-AC_INIT([eiciel],[0.9.11],[rofirrim@gmail.com])
+AC_INIT([eiciel],[0.9.12],[rofirrim@gmail.com])
 
 dnl Where are we
 AC_CANONICAL_BUILD

src/Makefile.am

@@ -63,13 +63,13 @@ endif
 endif
 
 desktopfilesdir=@datadir@/applications
-desktopfiles_DATA=eiciel.desktop
+desktopfiles_DATA=org.roger-ferrer.Eiciel.desktop
 
 
-appdatadir = $(datarootdir)/appdata
-dist_appdata_DATA = eiciel.appdata.xml
+appdatadir = $(datarootdir)/metainfo
+dist_appdata_DATA = org.roger-ferrer.Eiciel.appdata.xml
 
-eiciel.desktop : eiciel.desktop.in
+org.roger-ferrer.Eiciel.desktop : eiciel.desktop.in
 	$(AM_V_GEN)sed -e "s|@DSK_VERSION@|$(VERSION)|;s|@DSK_bindir@|$(bindir)|;s|@DSK_pkgdatadir@|$(pkgdatadir)|" $< > $@
 
 CLEANFILES = 
@@ -80,4 +80,4 @@ CLEANFILES += eiciel.desktop
 
 EXTRA_DIST= \
 	eiciel.desktop.in \
-	eiciel.appdata.xml
+	org.roger-ferrer.Eiciel.appdata.xml

src/org.roger-ferrer.Eiciel.appdata.xml

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- Copyright 2018 Roger Ferrer <rofirrim@gmail.com> -->
+<component type="desktop-application">
+    <id>org.roger-ferrer.Eiciel</id>
+    <metadata_license>CC0-1.0</metadata_license>
+    <project_license>GPL-2.0+</project_license>
+    <name>Eiciel</name>
+    <summary>Tool to manipulate ACL entries</summary>
+    <description>
+        <p>
+            Eiciel is a standalone tool and a Nautilus plugin to graphically
+            edit Access Control Lists (ACL) of your files. ACLs allow to set
+            more fine-grained permissions than the traditional Unix permissions
+            of user, group, other (UGO permissions).
+        </p>
+        <p>
+            Eiciel also allows to edit the extended attributes of files and
+            directories if the filesystem supports it.
+        </p>
+        <p>
+            Not all filesystems support ACLs and extended attributes. And even for
+            those supporting them, they must be enabled (by the system administrator)
+            before using Eiciel.
+        </p>
+    </description>
+    <launchable type="desktop-id">org.roger-ferrer.Eiciel.desktop</launchable>
+ <screenshots>
+  <screenshot type="default" width="1168" height="657">http://rofi.roger-ferrer.org/eiciel/gfx/shots/screenshot-appdata.png</screenshot>
+ </screenshots>
+ <url type="homepage">http://rofi.roger-ferrer.org/eiciel/</url>
+ <developer_name>Roger Ferrer Ibáñez</developer_name>
+</component>