fixed issue: loading under linux

Window icon was causing issues, so I made it optional.

README.txt

@@ -4,16 +4,16 @@ The Burning Wheel game system.
 Main Features:
     Shows intermediate distillations
     Allows for up to 14 facets
-    Allows for up to 10 of any sigils*
+    Allows for up to 10 of any of the sigils* (except 'Cap')
     Optional 'Advanced Limiting' to help keep the spell 'legal'
     Warns you if the spell is incomplete or house-ruled
     If the spell is damaging, it will display the weapon stats
     
     * 'Advanced Limiting' will limit the amount of some sigils
-    * Obviously the Cap Sigil is either on or off
 
 Requirements:
     Python 3.x or greater (tested on Python 3.2.3 32/64bit)
+    Should work on Windows, MacOS X, & Linux (tested on Windows 7/XP, and Ubuntu)
 
 To Do:
     save/load spells

SpellBurner.pyw

@@ -1,7 +1,7 @@
 # Burning Wheel - Spell Burner
 # By 2Shirt (Alan Mason)
 #
-# Version 1.0
+# Version 1.1
 from tkinter import *
 from tkinter import ttk
 from math import ceil, floor, log
@@ -948,7 +948,13 @@ class App(ttk.Frame):
 
 root = Tk()
 root.title('Spell Burner')
+if root.tk.call('tk', 'windowingsystem') == 'win32':
+    # Enable icon only under windows
+    # ToDo: fix for Linux/MacOS X
+    try:
         root.iconbitmap("SpellBurner.ico")
+    except TclError:
+        pass
 #root.resizable(0, 0)                       # disable window resizing
 root.resizable(width=FALSE, height=FALSE)   # disable window resizing
 root.option_add('*tearOff', FALSE)