g.region: Add more detail into LL error messages (#1988)

When setting up region in LL, this adds the actual values to the error messages in case these are computed
in the g.region call or function call itself. The value may also provide more explanation to what was actually violated.

Similar to #1140 (e0ce1558e6d4bda6b9d189a308941cc67222e366) but for the lat-lon extent cases.

lib/gis/adj_cellhd.c

@@ -440,7 +440,7 @@ static int ll_check_ns(struct Cell_head *cellhd)
 	    }
 	}
 	else
-	    G_fatal_error(_("Illegal latitude for North"));
+	    G_fatal_error(_("Illegal latitude for North: %g"), cellhd->north);
     }
 
     /* south */
@@ -490,7 +490,7 @@ static int ll_check_ns(struct Cell_head *cellhd)
 	    }
 	}
 	else
-	    G_fatal_error(_("Illegal latitude for South"));
+	    G_fatal_error(_("Illegal latitude for South: %g"), cellhd->south);
     }
 
     if (lladjust)
@@ -525,8 +525,9 @@ static int ll_check_ew(struct Cell_head *cellhd)
     if (cellhd->east - cellhd->west > 360.0) {
 	diff = (cellhd->east - cellhd->west - 360.0) / cellhd->ew_res;
 	if (diff > fpepsilon)
-	    G_important_message(_("360 degree EW extent is exceeded by %g cells"),
-		      diff);
+	    G_important_message(_("360 degree EW extent is exceeded by %g cells"
+		" (East: %g, West: %g)"),
+		      diff, cellhd->east, cellhd->west);
     }
     else if (cellhd->east - cellhd->west < 360.0) {
 	diff = (360.0 - (cellhd->east - cellhd->west)) / cellhd->ew_res;