CEF backend is built by default (unless --no-cef)

Issue: #372

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>

README.md

@@ -124,6 +124,7 @@ Build and Install
   * libuuid
   * libsecret-1 >= 0.16
   * g-ir-compiler
+  * [ValaCEF](https://github.com/tiliado/valacef) or configure with `--no-cef`
   * unity >= 3.0 or configure with `--no-unity`
   * dbusmenu-glib-0.4 >= 0.4 or configure with `--no-appindicator`
   * appindicator3-0.1 >= 0.4 or configure with `--no-appindicator`

wscript

@@ -231,8 +231,8 @@ def options(ctx):
 		'--webkitgtk-supports-mse', action='store_true', default=False, dest='webkit_mse',
 		help="Use only if you are absolutely sure that your particular build of the WebKitGTK library supports Media Source Extension (as of 2.15.3, it is disabled by default)")
 	ctx.add_option(
-		'--cef', action='store_true', default=False, dest='cef',
-		help="Build experimental CEF backend.")
+		'--no-cef', action='store_false', default=True, dest='cef',
+		help="Don't build experimental CEF backend depending on ValaCEF.")
 	ctx.add_option(
 		'--cef-default', action='store_true', default=False, dest='cef_default',
 		help="Whether the CEF engine should be default.")
@@ -354,7 +354,7 @@ def configure(ctx):
 	if ctx.options.cef_default:
 		ctx.options.cef = True
 	ctx.env.have_cef = ctx.options.cef
-	if ctx.options.cef:
+	if ctx.env.have_cef:
 		pkgconfig(ctx, 'valacef', 'VALACEF', '3.0')
 		pkgconfig(ctx, 'valacefgtk', 'VALACEFGTK', '3.0')
 		vala_def(ctx, "HAVE_CEF")