Merge pull request #1021 from heuripedes/master

C++ build fixes
(GLUI) Silence warning
Split up string_list functions into its own object/source file
Add string_list.c/string_list.h
Split up dir_list functions into its own source/object file
(Android) Fix JNI build
(PS3/Wii/PSP) Fix Salamander build
(360/Xbox 1) Fix Salamander builds
(iOS) Fix build
(file_path.h) Cleanups
(GLUI) Turn box_message into char variable of fixed size
(dspfilter.h) style/indent nits
Create config_file_userdata.c
Use config_file_userdata for gfx_filter