had to harden the work model against works without editions to pass
tests
Lagos 2060 will need 1st author to change back
added work.authors_short to work model and to search work mock model
used work #415 as an example of a work with 3 authors
The reason for doing this is so a library can put in money with one
check, then use it up gradually. (we get to pocket the fees that would
go to stripe) One change here- in b2u there is an extra click to get to
download page, even if no gift credit is involved - this way the user
knows what and how he's bee charged
eric