Prohibited characters in filenames

[fospald]

The colon (:) should be also replaced in doi2pdfname.py (and probably other files?)
to be compatible with Mac OS Classic.

For Windows also these characters should be replaced:

< (less than)
> (greater than)
: (colon - sometimes works, but is actually NTFS Alternate Data Streams)
" (double quote)
/ (forward slash)
\ (backslash)
| (vertical bar or pipe)
? (question mark)
* (asterisk)