Removing idInternal getters from RootDomainObject

  * See #5
Replacing 'idInternal' with 'externalId'

  * See #5
Replaced RootDomainObject.readXPTOByOID with AbstractDomainObject.fromExternalId

  * Also organized imports
  * See	 #5
Resolving compilation errors

  * See	  #5
Forms declarations now using String instead of Integer

  * Also fixed more compilation errors
  * See	 #5
Refactor: AnnouncementManagement now points to the External ID of the boards, instead of the idInternal

  * See	  #5
Refactor: Removed domain slots containing id internals.

  * See	  #5
Refactor: File's readByExternalStorageId now uses OID instead of Id Internal

  * See	  #5
Resolved more compilation errors

  * See	 #5
Removing Integer.valueOf in request.setAttribute

  * See	 #5
Fixing JSPs: Using the correct type and imports

  * See #5
Refactor: Fixed externalId.equals

  * See #5
Forms return an empty String as a default value. Changing the code to be aware of that

  * See	#5
Added getDomainObject(DynaActionForm, String)

  * This way form External Id Values can be safely used, as the
    default value for a String is ""
  * See	#5