If enabled, this will convert tags of the form "a,b,c" to a list and use
the results to create additional inventory groups.
This is based on PR #8676 by nickpeck (but not a straight rebase—both
the code and the nomenclature have been changed here).
Closes#8676
Introduces destination_format and destination_format_tags
to allow the construction of host names based on one or
more ec2 tags and a python format string.
renamed plugins to contrib (they are not really plugins)
rewrote README.md to reflect new usage
added new dir to setup.py so it gets copied with installation, in views
of making using inventory scripts easier in teh future
