setup.py still has references to nova/compute and was missing some
requires statements, and more importantly didn't hvae the install_requires.
Also, tools/pip-requires needed lxml versions set, as well as
added the missing setuptools_git entry.
This was exposed when trying to run Grenade as the requires.txt
file was never generated.
Fixes bug #1055693
Change-Id: Iaf9669d66e89507989ef3fde630dc2b488a97cfc