Fix EZP-21920: do not raise exception on loadRelations

refactored to reduce overhead,
normalized list building. removed temp var
seems there's nothing further to check. removing todo note
Fix EZP-21928: [SensioLabsInsight] Unused use statement should be avoided

Closes #611
EZP-21344: Fixed CreateView XML example in REST specs
Fix EZP-21933: [SensioLabsInsight] Unused method, property, variable or
parameter

See:
* https://jira.ez.no/browse/EZP-21933
* https://insight.sensiolabs.com/projects/0885c0ce-4b9f-4b89-aa9c-e8f9f7a315e0/analyses/9#rule-35-020
Merge pull request #605 from ezsystems/21920_loadrelation_remove_exception

Fix EZP-21920: do not raise exception on loadRelations
Fix CS nitpicks
Merge pull request #612 from ezsystems/fix_EZP-21933_unusedVariablesMethods

Fix EZP-21933: [SensioLabsInsight] Unused method, property, variable or parameter
Tests: added missing @covers
Fix EZP-21928: Unused use statement should be avoided, take 2
Fix EZP-21934: [SensioLabsInsight] Boolean property should not be prefixed by "is"

See:
* https://jira.ez.no/browse/EZP-21934
* https://insight.sensiolabs.com/projects/0885c0ce-4b9f-4b89-aa9c-e8f9f7a315e0/analyses/10#rule-37-060
Added SensioLabsInsight badge to Readme.md
Merge pull request #599 from joaoinacio/EZP-21916_http_purge_server_auth

Fix EZP-21916: basic auth in http cache purge_servers
Merge pull request #578 from joaoinacio/EZP-21840_shebang_in_legacy_script

Fix EZP-21840: unwanted "shebang" line running ezpublish:legacy:script
Added Helper and Pagination to phpunit.xml
Fix extra directory slash in phpunit-integration-legacy.xml
Merge pull request #618 from joaoinacio/EZP-21995_restricted_content_http500

Fix EZP-21955: Access to restricted content results in error 500
Fix EZP-21438: Improve permission handling to use view_embed