v.proj: reword description of -b flag and add mention of it to man page

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@69961 15284696-431f-4ddb-bdfa-cd5b030d7da7

vector/v.proj/main.c

@@ -128,7 +128,7 @@ int main(int argc, char *argv[])
     flag.no_topol = G_define_flag();
     flag.no_topol->key = 'b';
     flag.no_topol->label = _("Do not build vector topology");
-    flag.no_topol->description = _("Recommended for massive point conversion");
+    flag.no_topol->description = _("Recommended for massive point projection");
 
     /* The parser checks if the map already exists in current mapset,
        we switch out the check and do it

vector/v.proj/v.proj.html

@@ -36,6 +36,10 @@ appropriate, but can cause errors the input vector crosses the datum line
 at 180E/W. In this case wrapping of east coordinates to -180,180 needs 
 to be disabled with the <b>-w</b> flag.
 
+<p>When reprojecting massive point clouds for which topology is not necessary,
+the user can set the <b>-b</b> flag to suppress the building of topology of
+the output map.
+
 <p>
 In order to preserve spatial detail, <em>v.proj</em> performs automated
 vertex densification (as an alternative, <em><a href="v.split.html">v.split</a></em>