attach-related-media

Issue 2188: Allow Organization manager to add media content 

The goal is to give Organization manager possibility to link related media to Organizations 
same way as related media can be linked to APIs.

Implementation alternatives:

1. Replicate existing related media functionality concerning APIs

	What needs to be done:
	- copy existing code in api_media (and in subdirectories)
	- create new directory (e.g. organization_media)
	- paste existing code, collections and helpers
	- rename components, fields and collections (e.g. api --> org)
	- replace references to Apis collection with references to Organizations collection
	- replace references to Apis collection helpers with references to Organization	collection helpers
	- add call for orgRelatedMedia template into organizationApis template
  
	Pros and cons
  
	Pros:
	- straight-forward solution implementation
	- testing is easier, when new functionality does not affect existing API related media functionality 
  
	Cons:
	- redundancy both in code and in collection, in case in future changes are needed in related media functionality in general, 
  	  the changes need to be implemented twice


2. Generalize existing related media functionality concerning APIs so that it can also be used with Organizations

	What needs to be done:
	- in code: get indication whether related media in question is linked to APIs or to Organizations
	- rename components (not any more apiSomething but a general prefix)
	- change references to Apis collection to be selections between Apis collection and Organizations collection
	- change references to Apis collection helpers to be selections between Apis collection helpers and Organization collection helpers
	- postsSchema collection (probably needs to be destroyed and recreated)
		- in case mongo collection _id's are unique on db level, 
      		  same id field can be used for both API related medias and Organization related medias
		- in case we can not trust _id's uniqueness, there are two options
			- a) a separate id field for APIs and for Organizations (<-- perhaps most feasible)
			- b) new field to indicate, whether the id is for API or for Organization
	- add call for orgRelatedMedia template into organizationApis template
  
	Pros and cons
  
	Pros:
	- no redundancy either in code or in collections
	- in future possible changes need to be implemented only in one place
	  
	Cons:
	- more complicated solution to implement, when existing code needs to be generalized
  	- needs testing both old and new functionality