hand-operated manual tool for use with the bracing, leveling, supporting and setting of upright non-metal structural members and horizontal non-metal structural members during installation of non-metal fence posts so as to facilitate installation of fences; hand-operated tool for use for maintaining the desired angle and pitch of a non-metal beam, a non-metal post, a non-metal pillar, a non-metal mast or an upright non-metal structural member during installation of fences