tokuhirom/Furl — pull request #38 by syohex (2012-09-24 14:07:59+00:00)
Title: Fixed wrong dereference and add its test.

Furl->agent does not work well, because its dereference is wrong.

Output t/300_high/02_agent.t with original code
````
t/300_high/02_agent.t .. Can't call method "agent" on an undefined value
at /home/syohei/program/perl/Furl/blib/lib/Furl.pm line 29.
````

`$$_[0]` means `${$_}[0]`, not `${$_[0]}`.