Empty dictionary items cause filtering to fail

[Rick Barrett]

The dictionary comprehension in InitTree creates a ValueError exception if the XML contains a standalone tag like <description /> because that's parsed as None rather than an empty string.

Possible Fixes:

Stop the install log from writing those (a good idea anyway

Add a try block on the comprehension (filtering still fails)

Adjust xmlToTreeDict so those parse as empty strings instead of None

[Rick Barrett]

Fixed in 9f7061ad