Made a fundamenta change to the chaining algorithm on a whim.

Rather than chaining off of a single word--- which marko did previously--- marko now chains off of a chain.
Previously he would get a single word, get a rightbound sourceid, then start dropping chains. Then, when it finished the right side, marko would
turn around, go back to the source word, get a NEW (usually different) sourceid, then iterate left. This caused a lot of splicing in the
conversations and had a tendency to make it incoherent.

Now, marko grabs an entire chain cented around a word from source text. Due to this, I've lowered the recommended min/max chain length from 4 to
8 to 4 to 6.