pep8'd sugar3.activity
pep8'd sugar3.bundle
pep8'd sugar3.datastore
pep8'd sugar3.dispatch
pep8'd sugar3.graphics
pep8'd sugar3.presence
pep8'd sugar3.test
pep8'd sugar3
pep8'd examples
pep8'd tests
Resync with the sugar-build implementation of tree.py

Development continued there for a while. Now I will remove it
and used the toolkit implementation instead.

Changes:

* Retry faster
* Handle GLib errors
* Don't always dump the tree
* Support master atspi api
Merge pull request #2 from dnarvaez/sbtree

Resync with the sugar-build implementation of tree.py
Add a UIUnitTest class

To make it easier to write UI unit tests.
Don't set atspi timeout

Looking at the code I'm unconvinced this behaves as expected,
in certain cases at least. So reverting it for now to avoid
confusion.
Merge branch 'unittest' of https://github.com/dnarvaez/sugar-toolkit-gtk3 into dnarvaez-unittest