(#18092) Use CGI.parse on network URI query

The current implementation of the network device enable password parsing
is unable to handle characters like sharps and spaces in the password,
which are valid passwords. This commit adds CGI parsing of the query
string to only extract and unescape the enable query parameter.

This supercedes GH-1327 and GH-1491.
(#17864) Don't check certificate_revocation if configured not to
(#19493) suggest a 'specifications/lib' symlink to make puppet.gemspec's require work
(#19495) show how to run tests for n00bs like me
Merge pull request #1501 from adrienthebo/18092-cgi_unescape_enable_password

(#18092) Use CGI.parse on network URI query
(maint) Refactor ssl/host_spec.rb crl context

The tests added in 81a5cbb added more checks around the
certificate_revocation setting and overrided the local context settings.
This commit splits the rspec context into two smaller contexts for each
possible case and sets values in the before block accordingly.
Merge branch 'pull-1504'

This closes GH-1504.
Merge pull request #1505 from djmitche/fix/bug19493/master

(#19493) suggest a 'specifications/lib' symlink to make puppet.gemspec's require work
(maint) update README_DEVELOPER.md with rake spec details
Merge branch 'pull-1506'