extend plugin dsl for ohai 7. separate plugin loading.
convert plugins to new dsl.
updated and added spec tests for new dsl
update spec tests for compat with new dsl
Merge pull request #166 from opscode/OHAI-9015

Introduction of new DSL for OHAI
remove debug gems
Merge remote-tracking branch 'opscode/master' into tn/ohai-int-test
Changed OhaiPluginCommon to use the new way of running plugins
Added work around because 'depends' doesn't work yet