Fix glib/librsvg deprecation

librsvg: Only inlcude rsvg.h and remove calls to rsvg_init
glib: Remove call to g_thread_init and use g_value_*_schar
Use new GLib threading API

Based on eog commit by Felix Riemann <friemann@gnome.org>
Url: https://git.gnome.org/browse/eog/commit/?id=b5f61d90d0478378cf7cf21bf5ade9eded0ae9f2
Drop support for glib < 2.36
Use gtk_widget_hide instead of gtk_widget_hide_all

gtk_widget_hide_all is deprecated in gtk+2.24 for gtk_widget_hide.
Drop support for gtk+ < 2.24
Remove all calls to gtk_dialog_set_has_separator
Remove has_searator property from ui files
Bump librsvg minimum version to 2.36.2

We removed rsvg_init and cleaned the includes but no bumped the min version.
Gtk+3: Do not call gtk_statusbar_set_has_resize_grip for statusbar-date
Use MateColorButton
Factor out the code to store a pixbuf in EomScrollView

Based on eog commit 4f432e981a956cd157ae3f190b9c7850a6f180d9
From Claudio Saavedra <csaavedra@igalia.com>
Store a cairo_surface_t in EomScrollView for the GdkPixbuf to be rendered

Based on eog commit 889f275e38d0a7dcf062f5c63b8efaebaa1ca14f
From Claudio Saavedra <csaavedra@igalia.com>
Use gdk_window_create_similar_surface() for EomScrollView

Based on eog commit 648302091b5517b5da96c4277fbee8f13c125938
From Claudio Saavedra <csaavedra@igalia.com>
Fully rely on cairo to render the image in EomScrollView

Based on eog commit 919929eea1d63380f773f9c0a339a32149e592ba
From Claudio Saavedra <csaavedra@igalia.com>
Enable double-buffer in EomScrollView

Based on eog commit f0410a55778e719da8f2b62f0e5060bb128f028e
From Claudio Saavedra <csaavedra@igalia.com>
Fix the SVG rendering

Based on eog commit 8654e7de549d8edf34c14f3f0a655d8773b1e433
From Claudio Saavedra <csaavedra@igalia.com>
Remove unneeded code

Based on eog commit bb9d00011e07e9ad68b5e4968a2c1e68596c5684
From Claudio Saavedra <csaavedra@igalia.com>
Replace GdkInterpType with cairo_filter_t in EomScrollView

Basedon eog commit 793ede27dd4cd0aa73d5e84cc478641e25424f54
From Claudio Saavedra <csaavedra@igalia.com>
Honour the antialiasing-in and antialiasing-out EomScrollView properties

Based on eog commit 9e6f9ee6ea2c0ca4338445a55ff3c6175ca6f623
From Claudio Saavedra <csaavedra@igalia.com>
Improve the rendering of scaled images

Based on eog commit 2be68aaee33e3e6732e512a22d9ee5b681e95cc5
From Claudio Saavedra <csaavedra@igalia.com>