add bizhawk .SaveRAM extension to auto update file picker filter

[atshane253]

bizhawk uses the .SaveRAM extension instead of .srm, so I added it to the filter on the autoupdate save file picker.

[Zarby89]

as far as i know Snes9X is the only emulator which is dumping the sram file into the .srm file every x seconds. that would be useless to add that if bizhawk is not able to dump saves unless you quit the emulator, let me know if there's an hidden function that is allow that in bizhawk and i'll add it ;)

[atshane253]

Check my bizhawk branch, I'm working on that part, too. bizhawk added a menu option to flush saveram, I exposed it to lua and hot keys, and wrote a lua script that checks bytes for the hud and flushes when they change. I should add that option to limit how often it saves, there's a lot of random changes to the sram as you play. I'm gonna try to get that all pulled into bizhawk this week.

[atshane253]

TASEmulators/BizHawk#827