allow for soft updating of global-requirements

This creates a devstack REQUIREMENTS_MODE which is how we handle
syncing of global requirements. The default is 'strict', which is
current behavior. There is a new 'soft' mode which does a
--soft-update for projects *not* found in projects.txt, which lets
them specify additional requirements.

Change-Id: I4aa606514131b5dde67d87f5c8db5a3f3e50fc03
Depends-On: I1f195ef9ff1509659848e14ec9936ff6f66a6496
Revert "Single quote iniset argument in merge_config_file"

This reverts commit e2c9fee8ed846aba124a2fc1bba245790ed7ba90.

We have decided that we don't want to support the json-style argument
as described by bug#1374118 (see thread at [1]).

This restores the old behavior of sending the argument in
double-quotes so environment variables get expanded.  As a bonus,
tests for this are added.

[1] http://lists.openstack.org/pipermail/openstack-dev/2014-October/049341.html

Change-Id: I9fc99f3716cc53366907878adb00ae6cf3898f14
Closes-Bug:#1386413
Fix up file-matching in bashate tox test

The current test does not match file files in /lib/* because the
-wholename command is missing the preceeding \*.  The whole command is
a little difficult to understand.

This re-lays the find command, using -prune to skip dot directories
and keeping a hopefully clearer flow of what is being matched.

Change-Id: Idd856e897ff97095fb116294a9187ff4b198fa26
Merge "allow for soft updating of global-requirements"
Add pcre devel package for Horizon

pyScss python module uses pcre if available for performance
and it is better to be installed.
This commit adds it for files/{apts,rpms}/horizon.

Change-Id: If711fa222d3f395efd670334c8a84f35d195dc25
Make allow_{resize|migrate}_to_same_host configurable

In preparation for supporting 2 node devstack jobs, where the first node
is an all in one and the second is a compute node. Make nova config
options allow_resize_to_same_host and allow_migrate_to_same_host
configurable so we can turn them off when we have two compute nodes.

Change-Id: If6989200b56c4597d6e8506d0dda2cc75d0881f1
Merge "Fix up file-matching in bashate tox test"
Merge "Revert "Single quote iniset argument in merge_config_file""
Merge "Make allow_{resize|migrate}_to_same_host configurable"
Merge commit 'refs/changes/03/127603/5' of git://gold.eng.hq.xensource.com/git/github/openstack-dev/devstack into tmpbranch
Merge commit 'refs/changes/11/129211/1' of git://gold.eng.hq.xensource.com/git/github/openstack-dev/devstack into tmpbranch