Add m4/sac-pkg-config.m4
Add m4/sac-pkg-config.m4

Fix build from git if you don't have packageconfig installed already.

unispeech/sofia-sip,BelledonneCommunications/sofia-sip,xhook/sofia-sip,unispeech/sofia-sip,BelledonneCommunications/sofia-sip,BelledonneCommunications/sofia-sip,erdincay/sofia-sip,unispeech/sofia-sip,erdincay/sofia-sip,xhook/sofia-sip,unispeech/sofia-sip,xhook/sofia-sip,BelledonneCommunications/sofia-sip,erdincay/sofia-sip,erdincay/sofia-sip,xhook/sofia-sip,xhook/sofia-sip