Mark old structural framing node as obsolete.
Small fix to obsolete error message.
Merge pull request #59 from Randy-Ma/Revit2015

Merge the Revit2014 branch to the Revit2015 branch
Merge remote-tracking branch 'origin/Revit2015' into MAGN-5417
Merge pull request #61 from DynamoDS/MAGN-5417

MAGN-5417 Mark old structural framing family as Obsolete.
Merge remote-tracking branch 'origin/Revit2015' into Revit2016