Changes to get parallel merging with chains that have sub-chains with different numbers of steps.
Details of changes:
- ChainMerging: makeChainSteps function now creates empty sequences when the input step is None. Also removed some commented code.
- MenuComponents: check for consistent number of sequences and chain dicts per step when creating hypos.
- LS2_v1: Add 3 emu chains. Two are primaries, the etcut1step chain is there to test merged chains with different numbers of steps.
Edited by Mark Andrew Owen