Merge pull request #57 from ahpook/master

Renames ARM-8 and ARM-9 to better reflect their scope
ARM-9 Add Description of the implementation of "Data in Modules"

This adds the description of "Data in Modules" from the earlier Google
Doc. Motivation, goals etc. are still standard template text.
Adds 'discussion' field to metadata.json
Add ARM-9 sections answering 'Why'
Merge branch 'hlindberg-master'

Closes #58