new logic to generate correlation, relates to issue #95 . Updated DB
schema !
remove unused function
Performance tweak

- User/Role not looked up recursively anymore for authorisation checks -
  improves performance significantly. Also, checking perm_add and
  perm_modify instead of doing a lookup in the ACL tables
rewrote fetching of the related events
cleanup crappy sanitization
Merge branch 'feature/correlation' into develop
Merge branch 'develop' of https://github.com/MISP/MISP into develop
fix sanitization in Logs
fix sanitization in Whitelist
fix sanitization in Servers #96
fix sanitization in Blacklists #96
fix sanitization in Users #96
fix sanitization in Attributes #96
fix sanitization in Roles #96
fix sanitization in Regexp #96
fix sanitization in Events #96
fix sanitization in AdminCrudComponent #96
fix sanitization in AppController #96
Merge branch 'feature/cleansanitize' into develop
Fixes #96
Integrated ownership, ACL and minor fixes

- Orgs can propose new attributes or changes to existing attributes for
  events that they do not own

- publishing users of the owner organisation can see, accept or discard
  them

- Reworked the access control

- minor fixes