Updating Composer dependencies

This will update the password_compat library and Symfony YAML Component
Removed unreachable code

exit() terminates execution of the script.
Shutdown functions and object destructors will always be executed, but there is no chance to execute $app->close(0);
[fix] Fix parent selector. Fixes #4665
[imp] Add ACL `core.options` and take care of display the fieldset. Closes #4975.
[CS] Code style fixes on the libraries/cms folder. Closes #4976
[imp] Introduce jquery formvalidator for com_config. Closes #5042
[imp] Introduce jquery formvalidator for com_menus. Closes #5047
[imp] Introduce jquery formvalidator for com_users. Closes #5058
[imp] Introduce jquery formvalidator for com_contact ::frontend. Closes #5112
[imp] Introduce jquery formvalidator for com_mailto ::frontend. Closes #5114
[imp] Introduce jquery formvalidator for com_tags ::frontend. Closes #5116
Codestyle
[CS] com_mailto frontend. Closes #5072. Closes #5071.
[fix] Cannot add article in Joomla 3.2 with PostgreSQL. Fixes #4687
[fix] Use API to get month and year. Fixes #5244.
[Fix] Sample Data - park blogs module got wrong category. Fixes #5260
[fix] Sample Data - park blogs module wrong category. Fixes #5261.
Merge pull request #5226 from demis-palma/patch-6

Removed unreachable code
Merge pull request #5163 from mbabker/ComposerUpdates

Updating Composer dependencies
[fix] Who's online module shows multiple entries for a user name. Fixes #5111