gplugin/gplugin

add additional search directories to find libperl (fixes issue that libperl is not found on openSUSE)

Testing Done:
built on openSUSE and Gentoo

Reviewed at https://reviews.imfreedom.org/r/851/
REVIEWBOARD_URL = "https://reviews.imfreedom.org/"
REPOSITORY = "gplugin/gplugin"
REPOSITORY_TYPE = "mercurial"
BRANCH = "default"
LAND_DEST_BRANCH = "default"
LAND_PUSH = False