Trying some GCC flags

Add initial port to GCW0

Update GCC version in README.md

Document SNESADVANCE_SPEEDHACKS flag

Change S9xPlaySample to use pointers

Experimental compilation with -Os

Change configuration directory to ~/.snes9x4d-ng

Fix help message

Add old version of C4 emulator from gameblabla/dumbsnes

Remove -Wno-narrowing, bump to gnu++14