D-Net

Add subscribers collection, DAO and controller| add not found exception & handler | add authorization handler (disabled for now)

adding statistics dao in community controller

A first for statistics collection and methods

1. DivId is related with >=1 Pages (not just 1).
2. Version changed to 1.0.0 (not backward compatible).
3. DivId creation added in mongo initializing script - version information added.

1. Added script to initialize mongo database with name "openaire_admin" - if database already exists nothing happens ('drop' variable set to false)

1. API to find divhelpcontents by div
2. API to find div by name

Added missing files from previous commit about DivId and DivHelpContent

1. Added DivId class and API : special classes to be used by explore portal pages which have steps
2. Added DivHelpContent class and API
3. Added parameter 'div' (true/false) in '/community' to get communities related to some divIds
4. Added parameter 'div' (true/false) in '/community/{pid}/pages' to get pages of a community, which are related to some divIds...

1. Change Community methods - use pid (community) to query (GET requests)
2. community/{pid}/page/toggle & community/{pid}/entity/toggle - use pid to identify community
3. New (/pagehelpcontent/save) and Update (/pagehelpcontent/update) APIs for helpcontents separated...

'pid' field added in entities and communities for queries by portal | page help contents ordered by placement and order when returned | api to get page help contents by community name or community id (again ordered): '/pagehelpcontent?community=' or '/pagehelpcontent?communityId=' | api to get specific page of community: '/community/{id}/pages?page_route='