slicetype: do not allow edge CUs to contribute to frame cost totals

(x264 does this, it seems to result in better cost estimates overall)
slicetype: fix eoln
lookahead: Initialise I frame MBs to zero. This parameter gets incremented in CUcost.
TcomPridiction : IP calculation for a Block and modified the src buffer
TComPrediction: rename file static variable
TComPrediction: cleanup xPredInterLumaBlk