(PUP-3003) Only bundle necessary directories

Previously, we bundled all of puppet, facter, hiera, mcollective, and
vendored ruby into the installer, which included many unneeded files,
e.g. spec, acceptance, etc.

This commit modifies the `stage` task to only copy necessary directories
from downloads to staging (everything in staging is included in the MSI)

MCollective's plugins directory is a special case, as are the ruby and
tools directories in our vendored ruby.

With this change, the PE MSI size is reduced from 21MB to 18MB, FOSS is
even less as it doesn't include mcollective. The installation
directory (uncompressed) changes from 67MB to 55MB.

As a result of this change, the following file is added (moved really) in
the new MSI:

Only in Puppet Enterprise new/misc: puppetres.dll

And the following files are no longer included:

C:\>diff -r "Puppet Enterprise" "Puppet Enterprise new"
Only in Puppet Enterprise/facter: COMMITTERS.md
Only in Puppet Enterprise/facter: CONTRIBUTING.md
Only in Puppet Enterprise/facter: Gemfile
Only in Puppet Enterprise/facter: LICENSE
Only in Puppet Enterprise/facter: README.md
Only in Puppet Enterprise/facter: Rakefile
Only in Puppet Enterprise/facter: acceptance
Only in Puppet Enterprise/facter: documentation
Only in Puppet Enterprise/facter: etc
Only in Puppet Enterprise/facter: ext
Only in Puppet Enterprise/facter: install.rb
Only in Puppet Enterprise/facter: libexec
Only in Puppet Enterprise/facter: man
Only in Puppet Enterprise/facter: schema
Only in Puppet Enterprise/facter: spec
Only in Puppet Enterprise/facter: tasks
Only in Puppet Enterprise/hiera: CONTRIBUTING.md
Only in Puppet Enterprise/hiera: COPYING
Only in Puppet Enterprise/hiera: Gemfile
Only in Puppet Enterprise/hiera: LICENSE
Only in Puppet Enterprise/hiera: README.md
Only in Puppet Enterprise/hiera: Rakefile
Only in Puppet Enterprise/hiera: acceptance_tests
Only in Puppet Enterprise/hiera: docs
Only in Puppet Enterprise/hiera: ext
Only in Puppet Enterprise/hiera: install.rb
Only in Puppet Enterprise/hiera: spec
Only in Puppet Enterprise/hiera: tasks
Only in Puppet Enterprise/mcollective: Gemfile
Only in Puppet Enterprise/mcollective: README
Only in Puppet Enterprise/mcollective: Rakefile
Only in Puppet Enterprise/mcollective: etc
Only in Puppet Enterprise/mcollective: ext
Only in Puppet Enterprise/mcollective: install.rb
Only in Puppet Enterprise/mcollective: mcollective.init
Only in Puppet Enterprise/mcollective: spec
Only in Puppet Enterprise/mcollective: website
Only in Puppet Enterprise/puppet: COMMITTERS.md
Only in Puppet Enterprise/puppet: CONTRIBUTING.md
Only in Puppet Enterprise/puppet: Gemfile
Only in Puppet Enterprise/puppet: LICENSE
Only in Puppet Enterprise/puppet: README.md
Only in Puppet Enterprise/puppet: Rakefile
Only in Puppet Enterprise/puppet: acceptance
Only in Puppet Enterprise/puppet: api
Only in Puppet Enterprise/puppet: autotest
Only in Puppet Enterprise/puppet: benchmarks
Only in Puppet Enterprise/puppet: conf
Only in Puppet Enterprise/puppet: docs
Only in Puppet Enterprise/puppet: examples
Only in Puppet Enterprise/puppet: ext
Only in Puppet Enterprise/puppet: install.rb
Only in Puppet Enterprise/puppet: man
Only in Puppet Enterprise/puppet: spec
Only in Puppet Enterprise/puppet: tasks
Only in Puppet Enterprise/puppet: util
Only in Puppet Enterprise/puppet: yardoc
Only in Puppet Enterprise/sys: 1368-fix-scheduled-task-crash.patch
Only in Puppet Enterprise/sys: CVE-2013-4363.txt
Only in Puppet Enterprise/sys: PUP-1283-Get-description-failures-are-not-exceptional.patch
Only in Puppet Enterprise/sys: PUP-2889-Rescue-LoadError-when-wevtapi.dll-can-t-be-loaded.patch
Only in Puppet Enterprise/sys: README.md
Only in Puppet Enterprise/sys: pe-1475-fix-cve-2013-4287.patch
Only in Puppet Enterprise/sys: pe-1950-fix-cve-2013-4363.patch