Merge pull request #1016 from lioncash/free

playlist: early exit if NULL is passed to content_playlist_free_entry
Add Playlist Directory path setting
Set history path to playlists directory if playlist directory
is non-NULL
Create playlist in playlist_read_file if it doesn't already
exist
Create write_empty_file helper function in file_path.c
(rewind.c) style/indent nits
Cleanups
Style/indent nits
(Menu) Take out RARCH_MENU_TOGGLE for old_input_state - no longer
needed
(Menu) Disable going back to main menu when pressing menu toggle button
(will later be exposed again as a toggleable option)
(Menu/Settings) Only show Core Disk Options if core supports it
(Lakka) Fix menu toggle
(Lakka) Implement setting cmd_trigger
(Menu) Refactor more code to menu_action.c
(RARCH_CONSOLE/RARCH_MOBILE) Add default playlist dir for consoles/mobile
dynamic: Sanitize against NULL in libretro_free_system_info