Menu theme overhaul.

The animated star background no longer exists. PocketSNES is now drawn in DejaVu Sans Semi-Condensed. Selected items are white on "GCW Zero red".
main.cpp: Actually save SRAM in S9xAutoSaveSRAM.
Menu theme: Fix.

Commit 6877cd84fbaa801f3d88df267309850d121e3026 introduced PNG files with bit depths that are unacceptable to the program.
menu.cpp, menu.h: Remove the Auto Save SRAM option from user-visible settings.
Menu: Case changes.
main.cpp: Save SRAM automatically after 1 second, as well as on exit if it is modified; do not sleep for 1 second when saving.