I'm using shlex to make sure that there are less quoting problems when splitting lines like:
```python
'''--global-options="--bindir='/bin/a b c d' --prefix=/opt"'''
```
The above should be split into:
```python
{ 'global_options': ['--bindir=/bin a b c d', '--prefix=/opt'] }
```

I tried extracting the outermost quoted string with regexes, but I couldn't come up with anything reliable.