Fix ticket #119 disallow current picture to be the collocated picture

In response to ticket#119, disallow encoder to choose the current picture as the collocated picture when it is the only reference picture; check at decoder side if the current picture is chosen as the collocated picture. This can be at a lower priority as the current software will not use temporal MV prediction for CPR mode.

changed title from disallow current picture to be the collocated picture to Fix ticket #119 disallow current picture to be the collocated picture

changed the description

The current code is not broken. This fix is to further ensure we will not have issue in case we only have current picture as single reference. Maybe we could merge it after VTM-3.

merged

mentioned in commit 6848c2c0