Remove nose things

We don't use nose anywhere in anything related to devstack. The only
legitimate OpenStack things that are still nose are horizon and swift
unittests, and it turns out we don't really run those in devstack.

Change-Id: I215e0f3664f269e0e1b8f5d5f9c70553dededddd
lib/dstat: Fix a comment

Apparently this file was copied from lib/apache.

Change-Id: Ie89d423ca225c697122820a1d9e859769aea9f86
Moving horizon compression offline

Making the horizon scss compilation and compression happen offline.
Potentially fixing an issue with parallel compression in devstack.

Related-Bug: #1345955
Change-Id: I066c80e06a92302a3f8dc5fd45d127fbde6cf99c
Merge "lib/dstat: Fix a comment"
Merge "Moving horizon compression offline"