pkg/45680: pkglint should know FETCH_USING=

[matthias.rampke%googlemail.com@localhost]

>Number:         45680
>Category:       pkg
>Synopsis:       pkglint should know FETCH_USING=
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Dec 03 20:05:00 +0000 2011
>Originator:     Matthias Rampke
>Release:        Mac OS X Lion
>Organization:
>Environment:
Darwin mb.local 11.2.0 Darwin Kernel Version 11.2.0: Tue Aug  9 20:54:00 PDT 
2011; root:xnu-1699.24.8~1/RELEASE_X86_64 x86_64
>Description:
pkglint complains about FETCH_USING being defined but not used which is 
incorrect.
>How-To-Repeat:
cd net/youtube-dl && pkglint
>Fix:
https://gist.github.com/1427975