incorrect parsing of id's containing quote characters.

[johntconklin]

The parser does not handle id's and attribute values containing quoted quote characters. In this example, attribute nodeattr of node foo should be -"foo"-.

import pydotplus

data = r'''
graph {
    foo [ nodeattr = "-\"foo\"-" ];
    bar [ nodeattr = "bar" ];
}
'''

p = pydotplus.graph_from_dot_data(data)
print(p.to_string())

But this fails to parse:

    foo [ nodeattr = "-\"foo\"-" ];
        ^
Expected "}" (at char 17), (line:3, col:9)