Adds two new configs:
* ignoreSections, array of section names that'll be compared
* ignoreLeadSection, bool for whether to ignore the lead section
Bug: T346949
Depends-On: I7ded925b91b1d86b3c76c4135c85a3f0be1dee5e
Change-Id: I44f18fadcafbe011008d8abff566e2ccd7682f4f
The URL parameter turns out to be a bit painful for people to use in
some situations.
Bug: T350749
Change-Id: I7c88dc604dd321a7c78810b21f7ad8306ff9dab6