bug 30159 paths are always from root

[John O'Brien]

I have pushed a some blackbox tests for review to determine if I am
going in the right direction on this.

The branch is here: https://code.launchpad.net/~jdobrien/bzr/bug30159

The tests are in bzrlib/tests/blackbox/test_status.py

In summary, the behavior of bzr status would be changed based on the cwd.

* if cwd is a parent folder of the file, the output would trace the path
down to the file: parent1/parent2/branch/sub/file.txt
* if cwd is in a sub folder of the file, the output would walk the path
up to the cwd. ../sub/file.txt
* if some cases above, the output would need to walk the path up the
folder structure output like ../../../../../sub/file.txt would be possible.

Please let me know if this is desired.

thanks,
John O'Brien