[PATCH 2 of 2] Fixed WSPLGEN classes. Allow 0 for 'to' in differences

[Wald Commits]

# HG changeset patch
# User Raimund Renkert <rrenkert at intevation.de>
# Date 1395238124 -3600
# Node ID 6b880df95a3a7ceb784371f33041bf685fce174a
# Parent  20053d86fa5e69d1345a1d4010d3ba94f8d902e2
Fixed WSPLGEN classes. Allow 0 for 'to' in differences.

diff -r 20053d86fa5e -r 6b880df95a3a artifacts/src/main/java/org/dive4elements/river/themes/ThemeDocument.java
--- a/artifacts/src/main/java/org/dive4elements/river/themes/ThemeDocument.java	Tue Mar 18 18:07:27 2014 +0100
+++ b/artifacts/src/main/java/org/dive4elements/river/themes/ThemeDocument.java	Wed Mar 19 15:08:44 2014 +0100
@@ -659,7 +659,7 @@
             ? parseColor(strEndColor)
             : new Color(2, 27, 42);
 
-        to = to != 0 ? to : 9999;
+        to = to >= 0 ? to : 9999;
         step = step != 0 ? step : to;
 
         int numClasses = (int)((to - from) / step);