[Biophp-dev] Filetype parsers, pass-by-reference

[S Clark]

Okay, just committed changes to parse.inc.php (just commenting out the 
'unset($source)' part) and the fasta and clustal parsers.

Quick note - it appears not possible to pass by reference AND have a default
value, so the fasta and clustal parsers can no longer be instantiated 
without explicitly passing something as a source.  (You CAN still pass a null
if you don't want to specify a source immediately on instantiation for some
reason, but you do have to pass SOMETHING.)  This doesn't affect their
use inside the Parse class, though, since Parse also has to be instantiated
with a source defined.

Test script still works with both of those parsers, so we should be okay.