(QA-816) beaker vagrant support requires ruby 1.9+

- remove references to popen3 and use backticks
- can we please deprecate ruby 1.8 support?  please?
[maint] Do not modify the options hash in apply_manifest_on

1) This is just poor behavior
2) When an array of hosts is passed, apply_manifest_on is run more
than once. In this situation, the first one modifies the options hash
and ruins it for all its friends
Merge pull request #147 from branan/we_wouldnt_have_this_problem_in_clojure

[maint] Do not modify the options hash in apply_manifest_on
(QA-841) Windows complains about colons in sir names

Creating a directory with colons (':') in the name will fail on Windows
and prevent beaker from executing tests. This change moves from calling
%T to using %H_%M_%S for time-based directory names.
Merge pull request #153 from colinPL/invalid_dir_name

(QA-841) Windows complains about colons in dir names
Merge pull request #142 from anodelman/vagrant-1.8

(QA-816) beaker vagrant support requires ruby 1.9+
Add pe_ver ENV variable so we can control it outside the config files.
This can be handy when you want to test against different PE versions in jenkins for example.
(QA-806) have a means to dump env without running beaker test

- add --parse-only option to dump options and exit, useful for testing
(QA-845) Allow PE upgrade version to be specified in the config

Previously, when doing an upgrade beaker could only get a version by
reading the LATEST file. This makes it difficult to track exactly
which version is going to be tested in a given test run. By allowing
the version to be specified in the config file, we can make sure
beaker installs precisely the PE version that we care about for
testing.
(QA-787) Change default output to verbose
Merge pull request #154 from branan/programmable_upgrades

(QA-845) Allow PE upgrade version to be specified in the config
Merge pull request #133 from hunner/verbose_default

(QA-787) Change default output to verbose
Merge pull request #148 from anodelman/conf-only

(QA-806) have a means to dump env without running beaker test
(QA-794) make vagrant vm size configurable through beaker

- add support for a vagrant_memsize in the config file
- default to 1024
Merge pull request #141 from anodelman/vagrant-mem-size

(QA-794) make vagrant vm size configurable through beaker
create 1.7.0 beaker gem
Merge pull request #160 from anodelman/make-gem

create 1.7.0 beaker gem
(QENG-271) ability to set pe_ver/pe_dir as a default

- just add the check to see if pe_ver is set in options before
  attempting the version scraper
Merge pull request #162 from anodelman/pe-install-configuration

(QENG-271) ability to set pe_ver/pe_dir as a default
(maint) Don't munge the user's opts hash in `on`

Previously, if the user specified `:environment` in the opts to `on`
(or to a higher-level method that passes on opts to `on`), `on` would
delete that key when it was called. This not only makes it impossible
to call `on` sanely in a loop, but is generally a pretty shitty thing
to do to our users' data.

This changes the code to not modify the hash.