Data ind fails if the tree names are not "standard"

[Jon Hill]

Standard name = Hill_etal_2000_1
If the name is something else, Hill_etal_2000_tree1 then data independence fails:

Traceback (most recent call last):
   File
"/Applications/STK.app/Contents/Resources/lib/python2.7/site-packages/stk_gui/interface.py",
line 1284, in on_data_ind
     self.data_independence, self.new_phyml_data =
stk.data_independence(XML,make_new_xml=True,ignoreWarnings=False)
   File
"/Applications/STK.app/Contents/Resources/lib/python2.7/site-packages/stk/supertree_toolkit.py",
line 2227, in data_independence
     characters = get_characters_from_tree(XML, tree_name, sort=True)
   File
"/Applications/STK.app/Contents/Resources/lib/python2.7/site-packages/stk/supertree_toolkit.py",
line 1164, in get_characters_from_tree
     number = int(number.replace("_",""))
ValueError: invalid literal for int() with base 10: 'tree1'