Add missing entries in setup, fix up pip-requires

Add missing entries in setup, fix up pip-requires

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
(cherry picked from commit 7f00d13640edac8136241e546076f2106f7bfa61)