[BioC] download method in getBioC

[Jeff Gentry]

Hello ...

The latest version of getBioC (1.2.22) now supports alternate download
methods, re download.file().  Most users will not have any need to change
this from the default ("auto", just like in download.file()), but people
who are seeking to work around firewalls and proxies will probably need to
make use of things like the "wget" method.  To deviate from the default of
"auto", simply provide a 'method=XXX' parameter (where XXX is 'internal',
'wget' or 'lynx') to your getBioC call.

-Jeff