Update pitivi to 0.999

• Forcably load numpy as soon as possible so the required gcc library can get pulled in. This fixes the problem of not being able to find numpy at all.

PR: 172366
Submitted by: woodsb02@ (0.99 version + numpy patch),

		Olivier Duchateau (earlier version),
		Greg V (0.999 update)

Differential Revision: https://reviews.freebsd.org/D17042