OSError when passing config file to exiftool

[alexbruy]

When I try to init exiftool with custom config-file that describes some additional user tags I get this error:

  File "/home/alex/.qgis2/python/plugins/geotagphotos/exiftool.py", line 193, in __enter__
    self.start()
  File "/home/alex/.qgis2/python/plugins/geotagphotos/exiftool.py", line 176, in start
    stderr=devnull)
  File "/usr/lib64/python2.7/subprocess.py", line 679, in __init__
    errread, errwrite)
  File "/usr/lib64/python2.7/subprocess.py", line 1249, in _execute_child
    raise child_exception
OSError: [Errno 2] No such file or directory

Here is my simplified code:

etPath = "exiftool"
cfgFile = "/path/to/config/file"
etPath += " -config " + unicode(cfgFile)
et = exiftool.ExifTool(etPath)
with et:
  md = et.get_metadata("/path/to/photo")
  print md

Sample files:

• photo http://hub.qgis.org/attachments/5368/AM00100M_F1_20110930_1556.jpg
• config file http://hub.qgis.org/attachments/5369/.ExifTool_config

[alexbruy]

Forgot to say, that this code worked previously, but now master crashes

[alexbruy]

Just tested pull-request #5. When passing additional options using new optional parameter addedargs all works fine.
@smarnach any chance to merge it?