libinput: Add tap configuration to weston.ini

Enable by adding the following to your weston.ini:

[libinput]
enable_tap=true

This also makes weston require libinput >= 0.5.0.

Signed-off-by: Jonas Ådahl <jadahl@gmail.com>
diff --git a/weston.ini.in b/weston.ini.in
index 03fbde2..4fca0bb 100644
--- a/weston.ini.in
+++ b/weston.ini.in
@@ -61,6 +61,9 @@
 #mode=1024x768
 #transform=flipped-90
 
+#[libinput]
+#enable_tap=true
+
 #[touchpad]
 #constant_accel_factor = 50
 #min_accel_factor = 0.16