Quell the following intermittent errors that were occasionally displayed in
the browser:
    Undefined subroutine CGI::Pretty::delete_all
    at /opt/gbrowse/conf/plugins/PrimerDesigner.pm line 106
The comment above the END code block indicates that this code was for
mod_perl. The errors were observed under FastCGI.
Merge pull request #42 from nathanweeks/issue/primerdesigner_without_mod_perl

Quell intermittent PrimerDesigner errors when run under mod_fcgid instead of mod_perl.  Makes sense to me!