Opensong import fails on windows

[Tomas Groth]

Reproduced using OpenLP 2.1.1 and windows 8.1.

When importing an OpenSong xml we get the errormessage "Error parsing XML" and this traceback in the log:

2014-11-27 10:35:37,431 openlp.plugins.songs.lib.importers.opensong ERROR Error parsing XML
Traceback (most recent call last):
  File "Z:\home\tgc\OpenLP\bugfixes5\openlp\plugins\songs\lib\importers\opensong.py", line 139, in do_import_file
  File "lxml.objectify.pyx", line 1836, in lxml.objectify.parse (src\lxml\lxml.objectify.c:22650)
  File "lxml.etree.pyx", line 3239, in lxml.etree.parse (src\lxml\lxml.etree.c:69955)
  File "parser.pxi", line 1769, in lxml.etree._parseDocument (src\lxml\lxml.etree.c:102257)
  File "parser.pxi", line 1789, in lxml.etree._parseFilelikeDocument (src\lxml\lxml.etree.c:102516)
  File "parser.pxi", line 1684, in lxml.etree._parseDocFromFilelike (src\lxml\lxml.etree.c:101442)
  File "parser.pxi", line 1134, in lxml.etree._BaseParser._parseDocFromFilelike (src\lxml\lxml.etree.c:97069)
  File "parser.pxi", line 582, in lxml.etree._ParserContext._handleParseResultDoc (src\lxml\lxml.etree.c:91275)
  File "parser.pxi", line 683, in lxml.etree._handleParseResult (src\lxml\lxml.etree.c:92461)
  File "parser.pxi", line 622, in lxml.etree._raiseParseError (src\lxml\lxml.etree.c:91757)
  File "<string>", line None
lxml.etree.XMLSyntaxError: Start tag expected, '<' not found, line 1, column 1

Should be solved by opening the file in "rb" mode.