Community file sharing sample

@markewallace - Hi Mark. I finished the community file sharing sample (as detailed inhttps://hub.jazz.net/ccm01/resource/itemName/com.ibm.team.workitem.WorkItem/5854). Could you review this please?

(Will require merging of bug fixes to the file service by Vineet to work)

@markewallace - Hi Mark. I made the changes you recommended.