PrintReg: output to stderr

allows use of '-o -' while testing

Change-Id: Ibc02d7cede2df4eb8be0a28c0ca4bf5e91864191
Merge "PrintReg: output to stderr"
make VP8PredLuma4[] non-const and initialize array in VP8DspInit()

also convert 'type *dst' to 'type* dst'

Change-Id: I41ab66ad15b548cc45d1cb8b10bbca4fe1528cae
implement VE4/HE4/RD4/... in SSE2

(30% faster prediction functions, but overall speed-up is ~1% only)

Change-Id: I2c6e7074aa26a2359c9198a9015e5cbe143c2765