encoder assertion on the first picture when using JCTVC-J0513 encoder_lowdelay_P_3_2 coding structure. Patch attached.

There are two problems:

1. Current code ignores list of layers of an OLS associated with additional layer set when DefaultTargetOutputLayerIdc in layers.cfg is equal to 2.
2. After the modification made in Rev 982, the PTL index may not be assigned to each layer of OLS when DefaultTargetOutputLayerIdc is equal to 2

Patch to fix these problems is attached

The signalling of all_layers_idr_aligned_flag is different from the spec and may cause a bug.

When the following situation happen, the signalling is different from what is expected according to the spec:

• vps_vui_present_flag is equal to 1
• cross_layer_pic_type_aligned_flag is equal to 1

In such case, the cross_layer_irap_aligned_flag is not signalled but its value is inferred to be 1 (i.e., equal to vps_vui_present_flag) and the syntax element all_layers_idr_aligned_flag must be signalled.

However, with the current implementation, syntax element all_layers_idr_aligned_flag would not be signalled.

Patch to fix this is attached.