Changed from sys.argv to __file__

With sys.path the package depends on the fact that the mangle.pyw
launcher is exactly one directory under the package. __file__ on the
other hand, is relative to the package, so it does not matter where the
mangle.pyw file is or whether it even exists at all, thus making the
package self-contained. This is useful when putting the package in
site-packages and the launcher into $PATH.

mangle/util.py

@@ -14,10 +14,9 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
-import sys
 import os.path
 
 
 def buildResPath(relative):
-    directory = os.path.split(sys.argv[0])[0]
+    directory = os.path.dirname(__file__)
     return os.path.join(directory, relative)