barclamp_mgmt_lib: Fix crash when using --rpm mode

IO.popen() doesn't set $?, so we use `foo` to execute a command instead.
barclamp_mgmt_lib: Trust rpm if it returns an empty file list

If rpm exits with 0, then we should trust its output.
Merge pull request #1908 from VictorLowther/pull-req-master-fda77fb192c9c1d39e5891586544cf031c6d65bf

https://github.com/crowbar/crowbar/pull/1908

Merged by devtool for cloudedge
Merge pull request #1907 from vuntz/fix-rpm

barclamp_mgmt_lib: Fix crash when using --rpm mode
Added metadata for new release roxy
Use /var/run/crowbar for locking instead of /tmp

Using predictable filenames in /tmp for locking is not secure.
gitignore .swo
Merge branch 'master' of https://github.com/crowbar/crowbar
.swo and .swp added to gitignore
Merge pull request #1910 from juddmaltin-dell/master

+2 trivial
address directory missing issues in sledgehammer
improve error information when we have unparsable commit messages
add delayed job starts to tests server
only need 1 delayed_job
make delayed job STOP
Merge pull request #1911 from cloudedge/pull-req-master-659142f998ec3f393579a94f6beb129b886c15c8

Remove failing tests, make dev tests server add delayed job [2/2]
Merge pull request #1909 from vuntz/fix-chef-client-calls

Use /var/run/crowbar for locking instead of /tmp [2/2]
Change the admin node's bootenv from local to disk.
Install Postgres.
Pull in postgres 9.3