(#21272) Refactor created directory from 'puppet module generate'

Currently the created directory is 'username-modulename'.
This patch changes this to 'modulename' because that's mostly used.
(doc) Add documentation on rspec and mocha versions

Community members frequently experience issues running the specs because
of mismatched versions of RSpec and Mocha. This adds documentation to
the README_DEVELOPER.markdown and Gemfile to indicate the version
requirements and the reasons why those requirements are in place.
(maint) Move testing deps into Gemfile group
(#11317) - Do not ever skip resources appliable to both host and device

Since the puppet device feature introduction some types are labelled
as usable on host only, device only or both.

The schedule type is the only type that was labelled 'both'. Unfortunately
the logic in the Transaction#skip? was flawed and this resulted in all
the 'both' kind of resources to always being skipped, which essentially
meant that the Schedule type was non-working for a long time.

Signed-off-by: Brice Figureau <brice-puppet@daysofwonder.com>
Merge pull request #1714 from adrienthebo/doc-mocha_version_requirements

(doc) Add documentation on rspec and mocha versions
Merge pull request #1723 from masterzen/tickets/master/11317

(#11317) - Do not ever skip resources appliable to both host and device
OpenBSD has had flavors since the early 2000s at least; sync comment.
Merge pull request #1711 from electrical/rename_generate_dir

(#21272) Refactor created directory from 'puppet module generate'
(#16635) Respect http_proxy environment and settings in pkgdmg

In 3.x, the pkgdmg provider no longer honors http_proxy_host or http_proxy_port
settings or environment variables. This takes the methods to do this from
puppet/forge/repository and puts them in puppet/util/http_proxy, and updates
repository.rb and pkgdmg.rb to use it.
Merge branch 'pull-1719'

This closes GH-1719
Merge pull request #1749 from jasperla/flavors

OpenBSD has had flavors since the early 2000s at least; sync comment.