Adds "Release Notes/Known Bugs" to Changelog, updates file format to markdown, standardizes the format of previous entries

Per a request to have initial release notes that specifically listed known issues for this PE 3.2 release, and barred by time constraints from automating a pull from open issues in JIRA, this commit adds a Release Note and Known Bug section to the Changelog for the imminent 3.2 release. As it will display on the Forge, updates file type to markdown and standardizes previous entries. Adds template for release notes to be filled in later.
Merge pull request #87 from laurenrother/1.0.x

Adds "Release Notes/Known Bugs" to Changelog, updates file format to markdown, standardizes the format of previous entries
Add AIX and remove fields copied from Modulefile.
Merge pull request #88 from apenney/metadata

Add AIX and remove fields copied from Modulefile.
Prepare supported module 1.0.3.
Merge pull request #89 from apenney/102-supported

Prepare supported module 1.0.3.
Add missing fields back to work around Puppet bug.
Merge pull request #90 from apenney/last-minute-metadata-fix

Add missing fields back to work around Puppet bug.