Enable mouse support by default.

diff -u -r ../weechat-1.5/src/core/wee-config.c ./src/core/wee-config.c
--- ../weechat-1.5/src/core/wee-config.c	2016-05-01 06:50:12.000000000 -0400
+++ ./src/core/wee-config.c	2016-05-03 03:36:49.136508465 -0400
@@ -2993,7 +2993,7 @@
         weechat_config_file, ptr_section,
         "mouse", "boolean",
         N_("enable mouse support"),
-        NULL, 0, 0, "off", NULL, 0,
+        NULL, 0, 0, "on", NULL, 0,
         NULL, NULL, NULL,
         &config_change_mouse, NULL, NULL,
         NULL, NULL, NULL);