J. Andersen, A. Bene, and R. Penner. (2007)cite arxiv:0710.2651
Comment: 24 pages, 4 figures Theorem 3.6 has been strengthened, and Theorems
8.1 and 8.2 have been added.
A. Bene. (2010)cite arxiv:1010.5275
Comment: This survey (minus minor corrections) was written for and published
in the abstracts for the 57th Topology Symposium which took place in Okayama,
JP 2010. It summarizes the contents of a talk of the same title which
was given by the author at that conference on 8/12/2010.