Takes two optional arguments. The first argument is an epoch time you wish to
find the uploads since. If it is not supplied the default is the current time minus
one week. The second argument is the URL of a CPAN mirror you wish to query. If it
is not supplied then ftp://ftp.funet.fi/pub/CPAN/ is used.
In a list context it returns a list of uploaded distributions ordered by the time they were
uploaded (ie. oldest first, increasing in recentness ).
In a scalar context it returns a hash reference keyed on distribution with the values being the
epoch time that that distribution entered CPAN.