Update the README for 1.2.0

[hrydgard]

I'm sure I missed something as usual, please comment :)

[unknownbrackets]

Some others, not sure if they really need to be in though: #8096, #8225, #8330

I'm a bit short on time right now, here are some other that are maybe:
#8219, #8216, #8178, #8130, #8117, #8043, #8019, #8285, #8284, #8296, #8286, #8308, #8316, #8314, #8451

-[Unknown]

[sum2012]

Yes,missing "Combo Key"

[sum2012]

Fix video sound which has mono audio

[daniel229]

Support Eiyuu Densetsu: Sora no Kiseki Kai HD Remasters.#8314

[sum2012]

Support adhoc port offset

[vnctdj]

@hrydgard What about shrinking the file a bit ? I'm not sure we should keep all these very old versions...

[sum2012]

Yes,should move to history.txt