worked on volunteer activity custom data (CRM-12825)
Merge pull request #1 from yashodha/CRM-12825

worked on volunteer activity custom data (CRM-12825)
CRM-12825(added Volunteer Needs table)
added Volunteer role(CRM-12825)
Merge pull request #2 from yashodha/CRM-12825

Crm 12825
rename the table and columns, fix the activity type on install and uninstall(CRM-12825)
Merge pull request #3 from yashodha/CRM-12825

rename the table and columns,fix the activity type on install and uninstall