Merge pull request #1115 from lakkatv/xmb

(XMB) Remove uneeded headers
Pass index to 'list_delete' callback as well
Merge pull request #1116 from lakkatv/xmb

(XMB) Remove the xmb_ prefix of variables contained in the xmb_handler
Replace weird conditional with non-weird conditional.
Fix a leak here.
Revert "Fix a leak here." because it gives segfaults.

This reverts commit 156449ca9dc24db305617d2744e64bbbb308c815.
Fix use-after-free

menu_settings_iterate() would strcmp freed labels after exiting
a submenu.
Merge pull request #1117 from mprobinson/use-after-free

Fix use-after-free
Set rarch_settings_t * lists to NULL after setting_list_free calls -
messy manual bookkeeping
(XMB) Center messagebox