Clear global data on exit.

src/com/android/keepass/Database.java

@@ -91,6 +91,12 @@ public class Database {
 		}
 	}
 	
+	public static void clear() {
+		gGroups.clear();
+		gEntries.clear();
+		gRoot = null;
+		mPM = null;
+	}
 
 
 }

src/com/android/keepass/KeePass.java

@@ -60,7 +60,9 @@ public class KeePass extends Activity {
 	protected void onResume() {
 		super.onResume();
 		
+		// Clear password on Database state
 		setEditText(R.id.pass_password, "");
+		Database.clear(); 
 	}
 
 	@Override