As suggested by Joshua, this commit adds the 2-clause BSD license as a
comment block to the top of every source file.
For the first pass, I've just added myself for simplicity. I encourage
everyone to add themselves as copyright holders of any file they've
added or modified in some significant way. If I've added myself in
error somewhere, feel free to replace it with the appropriate copyright
holder instead.
Going forward, all new source files should include a license header.
We used to have two different models for displaying file system contents:
the FileManager-grade table-like directory model, which exposed rich data
(such as file icons with integrated image previews) about contents of a
single directory, and the tree-like GFileSystemModel, which only exposed
a tree of file names with very basic info about them.
This commit unifies the two. The new GFileSystemModel can be used both as a
tree-like and as a table-like model, or in fact in both ways simultaneously.
It exposes rich data about a file system subtree rooted at the given root.
The users of the two previous models are all ported to use this new model.
