Add new files required for project reference ordering

Thanks to Robin Neatherway for this.
Added additional references and new file to project
Added Send References Code to interactive pad

Also added addin.xml
Improved tooltip and autocompletion rendering

Still more work to be done in this area, mainly seperating out the
summary and signature.  There is a lot of complexity added to the
rendering that works on the assumption of a \n between the signature
ans markup, which might not always be the case.
Added DS_Store to ignore list
Merge pull request #139 from 7sharp9/master

Added tooltip and autocomplete improvements
More robust project parsing
Merge pull request #138 from bjwbell/master

More robust project file parsing
Fix installation of fsautocomplete on Linux
Ensure Emacs tests are picked up