reload repos with many -- in repo name if alternate_title exists

[eshellman]

suggested by @tfmorris: in #77
there is no reason not to use the alternative title in this case, since it's available:

https://github.com/GITenberg/------------------------------------------------------------13--------------------------_31434/blob/master/pg31434.rdf#L39

invesitigate something like https://pypi.python.org/pypi/transliterate/1.7.6

[tfmorris]

Did this turn out to be too hard to do? There's a commit that references this issue, but repo in the original issue still exists with the same name and, as far as I can tell, there's no better named version. That book also appears to be unfindable on the web site.

[eshellman]

This was implemented for new ebooks, so roughly #45000+. Thanks for the help.

A small number of of old repos have been renamed. This turned out to be really messy, because name skew broke things in the update chain. The code now depends on a lookup table which has to be frequently updated so that repo names don't changed when title metadata changes, which happens more often than you would think. For the PG implementation effort, we'll definitely NOT use anything other than book numbers in the repo names.