some filesystems are case insensitive, always use case insensitive lookup

oml/utils.py

@@ -440,3 +440,14 @@ def send_debug():
                     settings.server['last_debug'] = timestamp
     except:
         logger.debug('failed to send debug information')
+
+def iexists(path):
+    parts = path.split(os.sep)
+    name = parts[-1].lower()
+    if len(parts) == 1:
+        folder = '.'
+    else:
+        folder = os.path.dirname(path)
+    files = os.listdir(folder)
+    files = {os.path.basename(f).lower() for f in files}
+    return name in files