fix for g++:
	fix plVault LogMsg calls + remove useless wide char usage
	fix usage of plAvatarMgr::FindAvatar() and plLinkEffectsTriggerMsg::SetLinkKey() with temporary variables
	plNetServerSessionInfo.h need std::string
	fix plProgressMgr.h: NumLoadingFrames() have an useless class context information
	fix plSocket usage of non-standard NULL
Merge commit 'a1edba6'