Make scheduler_driver configurable

No scheduler_driver will be configured if none is provided.
Merge pull request #37 from mgagne/add_scheduler_driver

Make scheduler_driver configurable
update permission of paste config to 600

to ensure that any system users cannot read
credentials stored in the file.
Merge pull request #38 from bodepd/fix_cinder_paste_conf_permissions

update permission of paste config to 600
1.1.1
Merge pull request #40 from bodepd/1_1_1

1.1.1
Merge pull request #41 from puppetlabs/master

backport 1.1.1 release to folsom branch