[seed] Add support for new webkit version 4.0 to build system

[Alan Knowles <alank src gnome org>]

commit 6d512b5c4d774a9853b51dae464a10cea7e3423a
Author: Peter Rustler <peter rustler basyskom com>
Date:   Mon Dec 7 11:40:05 2015 +0000

    Add support for new webkit version 4.0 to build system
    
    Add new configure value for option --with-webkit.
    Now you can add 4.0 as value to --with-webkit.
    Default is still 3.0.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=759171

 configure.ac |   10 ++++++++--
 1 files changed, 8 insertions(+), 2 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 2313c09..3d5d482 100644
--- a/configure.ac
+++ b/configure.ac
@@ -77,12 +77,12 @@ dnl ==============================WebKit=======================================
 m4_define([webkit_default], [3.0])
 
 AC_ARG_WITH([webkit],
-            [AC_HELP_STRING([--with-webkit=@<:@3.0/1.0@:>@],
+            [AC_HELP_STRING([--with-webkit=@<:@4.0/3.0/1.0@:>@],
                             [Select the Webkit backend, default=3.0])],
            [],
             [with_webkit=webkit_default])
 
-dnl=== support both 1.0 and 3.0 (default 3.0) ==
+dnl=== support all 1.0, 3.0 and 4.0 (default 3.0) ==
 AS_CASE([$with_webkit],
        [3.0], [
                WEBKIT_PC=webkitgtk-3.0
@@ -90,6 +90,12 @@ AS_CASE([$with_webkit],
                AC_CHECK_LIB(webkitgtk-3.0, JSContextGroupCreate,,
                        AC_CHECK_LIB(javascriptcoregtk-3.0, 
JSContextGroupCreate,WEBKIT_PC=javascriptcoregtk-3.0)) 
        ],
+       [4.0], [
+               WEBKIT_PC=webkitgtk-4.0
+               SEED_GTK_VERSION=-gtk4
+               AC_CHECK_LIB(webkitgtk-4.0, JSContextGroupCreate,,
+                       AC_CHECK_LIB(javascriptcoregtk-4.0, 
JSContextGroupCreate,WEBKIT_PC=javascriptcoregtk-4.0))
+       ],
        [1.0], [
                AC_CHECK_LIB(webkitgtk-1.0, JSContextGroupCreate,WEBKIT_PC=webkitgtk-1.0,
                        AC_CHECK_LIB(javascriptcoregtk-1.0, 
JSContextGroupCreate,WEBKIT_PC=javascriptcoregtk-1.0,