Fix: RegularTriangulationTraits_3::Bare_point

Bug fixes in specification. The Regular_triangulation_3 template, does
require that its template parameter Gt has a nested type Gt::Bare_point.

Triangulation_3/doc_tex/Triangulation_3_ref/RegularTriangulationTraits_3.tex

@@ -48,6 +48,8 @@ point $p\in\R^3$ or the weighted point ${p}^{(w)}=(p,w_p)$.
 
 \ccTwo{RegularTriangulationTraits_3::Weighted_point_3xx}{}
 \ccNestedType{Weighted_point_3}{The weighted point type.}
+\ccGlue
+\ccNestedType{Bare_point}{The (un-weighted) point type.}
 
 \ccTwo{Regular}{}
 \ccNestedType{Power_test_3}