Merge pull request #161 from cxd4/master

temp. bypass to double each scanline for non-interlaced DAC
Lessen libretro hacks in cxd4-rsp/rsp.c
cxd4 - Remove some more hacks
(Angrylion) Take out excessive logspam
(Angrylion) Add core option for VI Overlay
`blitter_buf' needs to allocate space based on VI_V_SYNC_REG limit.