Add OstreeAsyncProgress, use it for ostree_repo_pull

Several APIs in libostree were moved there from the commandline code,
and have hardcoded g_print() for progress and notifications.  This
isn't useful for people who want to write PackageKit backends, custom
GUIs and the like.

From what I can tell, there isn't really a winning precedent in GLib
for progress notifications.

PackageKit has the model where the source has GObject properties that
change as async ops execute, which isn't bad...but I'd like something
a bit more general where say you can have multiple outstanding async
ops and sensibly track their state.

So, OstreeAsyncProgress is basically a threadsafe property bag with a
change notification signal.

Use this new API to move the GSConsole usage (i.e. g_print()) out from
libostree/ and into ostree/.

src/libostree/ostree-async-progress.h

@@ -0,0 +1,68 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright (C) 2013 Colin Walters <walters@verbum.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#pragma once
+
+#include "ostree-types.h"
+
+G_BEGIN_DECLS
+
+#define OSTREE_TYPE_ASYNC_PROGRESS         (ostree_async_progress_get_type ())
+#define OSTREE_ASYNC_PROGRESS(o)           (G_TYPE_CHECK_INSTANCE_CAST ((o), OSTREE_TYPE_ASYNC_PROGRESS, OstreeAsyncProgress))
+#define OSTREE_ASYNC_PROGRESS_CLASS(k)     (G_TYPE_CHECK_CLASS_CAST((k), OSTREE_TYPE_ASYNC_PROGRESS, OstreeAsyncProgressClass))
+#define OSTREE_IS_ASYNC_PROGRESS(o)        (G_TYPE_CHECK_INSTANCE_TYPE ((o), OSTREE_TYPE_ASYNC_PROGRESS))
+#define OSTREE_IS_ASYNC_PROGRESS_CLASS(k)  (G_TYPE_CHECK_CLASS_TYPE ((k), OSTREE_TYPE_ASYNC_PROGRESS))
+#define OSTREE_ASYNC_PROGRESS_GET_CLASS(o) (G_TYPE_INSTANCE_GET_CLASS ((o), OSTREE_TYPE_ASYNC_PROGRESS, OstreeAsyncProgressClass))
+
+typedef struct OstreeAsyncProgress   OstreeAsyncProgress;
+typedef struct OstreeAsyncProgressClass   OstreeAsyncProgressClass;
+
+struct OstreeAsyncProgressClass
+{
+  GObjectClass parent_class;
+
+  void (*changed) (OstreeAsyncProgress *self, gpointer user_data);
+};
+
+GType   ostree_async_progress_get_type (void) G_GNUC_CONST;
+
+OstreeAsyncProgress *ostree_async_progress_new (void);
+
+OstreeAsyncProgress *ostree_async_progress_new_and_connect (void (*changed) (OstreeAsyncProgress *self, gpointer user_data), gpointer user_data);
+
+char *ostree_async_progress_get_status (OstreeAsyncProgress       *self);
+
+guint ostree_async_progress_get_uint (OstreeAsyncProgress       *self,
+                                      const char                *key);
+guint64 ostree_async_progress_get_uint64 (OstreeAsyncProgress       *self,
+                                          const char                *key);
+
+void ostree_async_progress_set_status (OstreeAsyncProgress       *self,
+                                       const char                *status);
+
+void ostree_async_progress_set_uint (OstreeAsyncProgress       *self,
+                                     const char                *key,
+                                     guint                      value);
+void ostree_async_progress_set_uint64 (OstreeAsyncProgress       *self,
+                                       const char                *key,
+                                       guint64                    value);
+
+G_END_DECLS
+