Fix travel bundle view details click event (#7112)
Symfony framework upgrade to 2.6 (#7111)

Composer file updated, vendor library versions set to
match release ranges.
PHP unit vendor lib moved to require-dev.
New debug bundle enabled.
Deprecated form type option refactorization (#7111)

Form type classes have been updated and the deprecated
"empty_value" option changed to "placeholder".
Deprecated security context interface updates (#7111)

Unused security context DI removed from classes.
Security context DI changed to AuthorizationCheckerInterface
and TokenStorageInterface respectively.
Services xml files updated.
Affected classes matched against PSR standards.
Merge branch 'feature/7110-Upgrade-symfony-framework' (#7110)