add remove option (#1409)

Author: baltzell

common-tools/clas-utils/src/main/java/org/jlab/utils/options/OptionParser.java

@@ -70,7 +70,12 @@ public void addRequired(String key,String desc){
         option.setDescription(desc);
         requiredOptions.put(key, option);
     }
-    
+   
+    public void removeOption(String key) {
+        optionsDescriptors.remove(key);
+        requiredOptions.remove(key);
+    }
+
     public void addOption(String key, String defaultValue){
         check(key, optionsDescriptors.keySet());
         OptionValue option = new OptionValue(key,defaultValue);