new features for serial module :

new features for serial module :
- the last 5 issues are now shown, and their status can be changed (but not reverted to "waited", as there can be only one "waited")
- the library can create a "distribution list". this paper contains a list of borrowers (selected from the borrower list, or manually entered), and print it for a given issue. once printed, the sheet can be put on the issue and distributed to every reader on the list (one by one).