(maint) formatting

This removes trailing whitespaces in install_utils.rb
(QENG-1037) Install from git should accept depth

When installing from larger repositories, being able to specify depth can cut
the time of git checkout in half. This becomes especially helpful when you are
checking out multiple repositories.
Due to the older git on some of the templates, this provides the older
--branch name --depth 1 commands, which means when using depth, one should
ensure the rev passed is a branch and not a single commit. Alternatively one
can add depth_branch => 'name' to repository and have that used instead of rev.
(gh-426) Add prebuild packages to Dockerfile

Without this patch every time the specs run, prebuilt packages are
installed to the new docker image. Even when preserving the image.
To increase the speed of the test suite we install those packages when
creating the Docker image. The `HostPrebuiltSteps` checks whether those
are installed and does not do anything directly starting to execute the
specs inside the image.
Add Enterprise Linux (el)
(QENG-1033) combine two conditionals into a single statement
(QENG-1033) additional_pkgs should be a module level variable
(QENG-1033) Reset additional_pkgs in a way supported by all Ruby versions
(QENG-1033) Move all functionality into the Perf module and sync the rspec tests
(MAINT) add ability to list all instances associated with an ec2 keyname

- convenience function for listing all instances associated with a
  provided keyname, useful for tracking what's happening in ec2
(QENG-1128) Beaker no long auto recursively scps directories...

to systems under test

- issue was :recursive variable was being carried over successive calls
  to scp_to.  To prevent this, just set it based upon the file type
  being called
(QENG-1033) Remove dead rspec code
Merge pull request #416 from anodelman/ec2

(MAINT) add ability to list all instances associated with an ec2 keyname
Merge pull request #439 from doug-rosser/perf_fixes

(QENG-1033) Don't modify constants and properly support all Linux platforms in Perf
Merge pull request #435 from leoc/add-prebuilt-packages-to-docker

(gh-426) Add prebuild packages to Dockerfile
Merge pull request #388 from ferventcoder/ticket/master/allow-git-depth

(QENG-1037) Install from git should accept depth
(QENG-15) beaker openstack support (EXPERIMENTAL)

- experimental code to support openstack, may be missing configuration
  steps or otherwise be incomplete
- should be used as a basis for further beaker openstack infrastructure
Merge pull request #361 from anodelman/openstack

(QENG-15) support openstack in beaker
Merge pull request #450 from anodelman/scp-repair

(QENG-1128) Beaker no long auto recursively scps directories to systems under test
(QENG-1209) scp in debug output shows far too much output

- move detailed output into a new log level called 'trace', could still
  be useful for tracking networking failures - but will be disabled by
  default
- add ability to flip on/off quiet output to logging