Fix EZP-22308: store in db sortkey value (as in legacy) and return it while searching for relation
Fix EZP-22775: [API] Permissions should handle missing limitations gracefully

Some limitations are not implemented yet (like NewState), others that
are only relevant for legacy newer will be (ezjscore ajax call related).
So Permission checks should handle this and make sure that missing
limitation is threated as a "no access" instead of letting the exception
true.

- [ ] todo: Integration/ unit test
Merge pull request #839 from flovntp/EZP-22308_v2

Fix EZP-22308: store in db sortkey value (as in legacy) and return it while searching
Test EZP-22775: Add unit test coverage for exception handling
Merge pull request #851 from ezsystems/ezp-22775

[API] Permissions should handle missing limitations gracefully
[Travis] Simplify test matrix

- As unit tests on 5.3.3 are broken, move it out and only care about
integration tests there until it and 5.3 is soon removed (RHEL7).
- Remove Solr 3.6, mnot interesting now that we got legacy upgraded
to Solr 4.x.
- Move TimeZone out of matrix to make it slightly more readable.
- Update to use solr 4.7.2, similar as used in ezfind.
BDD: grab rest_url passed from behat.yml
Merge pull request #855 from ezsystems/simplify_travis_matrix

[Travis] Simplify test matrix
Merge pull request #856 from MLoureiro/pass_url_to_rest

BDD: grab rest_url passed from behat.yml
EZP-22617: Implement ISBN FieldType
Fix EZP-22617: Added tests (unit & integration)
CS
Fixed for unit tests
Fix EZP-22617: Use get function on fieldDefinition as assumed by tests
Fix EZP-22617: Add API integration test for ISBN and fix missing parts
Fix EZP-22617: Add Solr indexing config + cs