Parse hierarchical data

Add support for hierarchical data export via XML

#4, #2
Create UI

Setup initial UI to choose folder, pattern, and data file.
Starting with XML first.

#5
Add asynchronous processing

Use multiple threads to process multiple files at once.

#5
Show progress

Show progress bar.
Fixed parallel loop to use separate spiders.
Moved progress logic to separate class.
Cleaned up left over diagnostic code.
Clean up code style/issues.

#5