Add minimal support to `pkg-config imlib2`; imlib2-config has been
dropped since imlib2-1.7.5.

--- configure.orig	2005-06-26 14:22:29 UTC
+++ configure
@@ -8112,22 +8112,20 @@ fi
 echo "${ECHO_T}no" >&6
 fi
 
-if test "$IMLIB2_CONFIG_IN_PATH" != yes; then
-    echo "------- ERROR -------"
-    echo "The imlib2-config development script was not found in your execute path."
-    echo "You may have imlib2 installed somewhere not covered by your path."
-    echo ""
-    echo "If this is the case make sure you have the packages installed, AND"
-    echo "that the imlib2-config script is in your execute path (see your"
-    echo "shell's manual page on setting the \$PATH environment variable)."
-    echo "---------------------"
-    { { echo "$as_me:$LINENO: error: Fatal Error: no imlib2-config detected." >&5
-echo "$as_me: error: Fatal Error: no imlib2-config detected." >&2;}
-   { (exit 1); exit 1; }; }
-    exit;
+if test "$IMLIB2_CONFIG_IN_PATH" = yes; then
+    imlib2_cflags=`imlib2-config --cflags`
+    imlib2_libs=`imlib2-config --libs`
+else
+    if pkg-config imlib2; then
+        imlib2_cflags=`pkg-config imlib2 --cflags`
+        imlib2_libs=`pkg-config imlib2 --libs`
+    else
+	{ { echo "$as_me:$LINENO: error: Fatal Error: no imlib2 detected." >&5
+	echo "$as_me: error: Fatal Error: no imlib2 detected." >&2;}
+	{ (exit 1); exit 1; }; }
+	exit;
+    fi
 fi
-imlib2_cflags=`imlib2-config --cflags`
-imlib2_libs=`imlib2-config --libs`