* Add USE_PERL_RUN and USE_PERL_BUILD to add {RUN,BUILD}_DEPENDS on the
perl5 port if required (i.e. on 5.0 or later) (USE_PERL adds both,
which is not always appropriate) [1]
* On 5.0 systems without perl, depend on the full path to the perl port
binaries to not pick up the system perl wrapper
* If PERL_CONFIGURE is defined, move the USE_PERL setting earlier in
the makefile so it actually adds a dependency. [2]
Noticed by: dougb [1]
Submitted by: sobomax [2]
Tested on: bento
a8090228ca