Python Fold Parser does not handle line continuation

[awindillman]

Python uses the backslash '' as a line continuation. If there is a line continuation anywhere in the RSTA while code folds are being processed an exception is thrown.

Steps to Reproduce
Specific steps to reproduce the behavior:

1. Launch the demo App
2. Go into Python mode
3. Add a line continuation after an if (for example) and add anything to the next line
4. Exception thrown

This bug requires adding support for line continuation to the PythonFoldParser. This is a small fix, and I will put in a pull request for it.

[bobbylight]

Thanks for the PR with the fix!