gplugin/gplugin

Don't bother looking for libperl on FreeBSD as it's there if the perl executable is installed.

Testing Done:
Tested on debian with and without libperl-dev installed as well as FreeBSD with perl installed.

Reviewed at https://reviews.imfreedom.org/r/246/
<?xml version="1.0" encoding="UTF-8"?>
<glade-catalog name="gplugin-gtk"
version="@GPLUGIN_VERSION@"
library="gplugin-gtk"
domain="gplugin"
depends="gtk+"
book="GPlugin">
<glade-widget-classes>
<!-- the get-type-function's are needed due to gplugin's weirdo namespace.
Without them, Glade is going to look for g_plugin_*_get_type and not
gplugin_*_get_type.
-->
<glade-widget-class
name="GPluginGtkPluginInfo"
generic-name="plugininfo"
title="Plugin Info"
get-type-function="gplugin_gtk_plugin_info_get_type"/>
<glade-widget-class
name="GPluginGtkView"
generic-name="pluginview"
title="Plugin View"
get-type-function="gplugin_gtk_view_get_type"/>
<glade-widget-class
name="GPluginGtkStore"
generic-name="pluginstore"
title="Plugin Store"
get-type-function="gplugin_gtk_store_get_type"
toplevel="True"/>
</glade-widget-classes>
<glade-widget-group name="gplugin-gtk" title="GPlugin Gtk Widgets">
<glade-widget-class-ref name="GPluginGtkPluginInfo"/>
<glade-widget-class-ref name="GPluginGtkView"/>
<glade-widget-class-ref name="GPluginGtkStore"/>
</glade-widget-group>
</glade-catalog>