fix pop error and supported linux path

run on ubuntu system
modified content:

supported linux path:
```
\\ convert to /
```

fix pop error:
```
Traceback (most recent call last):
  File "Necromonster.py", line 148, in <module>
    Necro()
  File "Necromonster.py", line 97, in __init__
    self.blit_list = mapLoader.load('home', self)
  File "class/mapLoader.py", line 12, in load
    l.pop()
IndexError: pop from empty list
```