api: add image_cache_dir parameter

Without image_cache_dir parameter, Glance API can't start.
Default value is set to /var/lib/glance/cache.

Change-Id: I1cfcbf0021cfae187d9c8d78a16b18de29c97b4a
Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>
Deprecate old SQL parameters

SQL configuration has changed in Havana.
This patch aims to deprecate old parameters and configure using the
right way.

Change-Id: I6a800d51294ae23636636a8d1c6ccad192f45d4e
Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>
(cherry picked from commit 8156a87cd04943904258d572e47838d0c346654f)
Fix could not find user glance on ensure files

commit 394661ec introduces a bug when the etc files ensure owner
'glance' run before the installation of the packages, and user glance
is not available, since this user is added by the package installation
after that.

This fix adds the dependency between packages and the ensure of etc
files.

Change-Id: Ia6523daf69f684c5bdb83255a8e6f6de3160ecc1