Finish updating standard template

This now works with Trusty cookbooks
Merge branch 'master' into ha-feature-trusty
Rework hostname generation

Avoid '--' when there is nothing in a name component
Remove Go 1.0.3
Destroy unusable VMs when errors occur
Merge branch 'master' into ha-feature-trusty

Conflicts:
	lib/travis/cloud_images/cli/image_creation.rb
Fix previous merge conflict correctly

The previous resolution resulted in a NameError.
Set custom_base_name explicitly

To think, base_image **could** be sent `nil`, so we need to
ensure that it is set to a reasonable value before sending it to
`#latest_template`.
Select base image based on the :name parameter

Note that the order in which the named components appear in
'name_pattern' (in `#base_image`) and 'desc' (in `#create`)
must match
Merge branch 'master' into ha-feature-trusty
Merge branch 'master' into ha-feature-trusty
Merge branch 'master' into ha-feature-trusty
Reformat template description

So that it is clear what components are available
Tweak output to include template description
Merge branch 'master' into ha-feature-trusty
Add a means of listing installed software versions

We add a YAML-driven way to list installed software versions
at the end of the template createion.
The commands to list the versions of the desired software
will be indicated in each worker.*.yml file as the
'list_versions_by' array.

In general, this array will be constructed by listing
apt packages, and using appropriate shell commands.
List software verions for standard image

* We want versions of the installed packages, so use 'dpkg --list'
* Some commands are installed only for 'travis' user
  (Ideally, we should parametrize the user name)
* Some commands are massaged so that the output is of the form
  "SOFTWARE_NAME VERSION"
List software versions for ruby templates
Print rvm version in standard images

This version is common to all images
List Python versions

~travis/virtualenv shows aliases as well
Also show the compile time options for the default version of Python
and modules installed by pip