Fix a bunch of -pedantic stuff

aegisub/libaegisub/common/cajun/elements.cpp

aegisub/libaegisub/common/vfr.cpp

aegisub/libaegisub/include/libaegisub/option.h

aegisub/libaegisub/include/libaegisub/option_value.h

aegisub/reporter/platform.cpp

aegisub/reporter/platform_unix_bsd.cpp

aegisub/src/aegisub_endian.h

aegisub/src/ass_file.h

aegisub/src/audio_box.cpp

aegisub/src/audio_controller.h

aegisub/src/audio_display.cpp

aegisub/src/audio_karaoke.cpp

aegisub/src/audio_player_oss.cpp

aegisub/src/auto4_base.cpp

aegisub/src/auto4_base.h

aegisub/src/auto4_lua.cpp

aegisub/src/auto4_lua.h

aegisub/src/auto4_lua_assfile.cpp

aegisub/src/auto4_lua_dialog.cpp

aegisub/src/auto4_lua_factory.h