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);
Add test for legacy failure
Use a default of 303 instead of an exception
Merge pull request #5290 from wilsonge/patch-27

Fix minor b/c break in https://github.com/joomla/joomla-cms/pull/4292
[fix] Apply on-the-fly class aliases, even for Composer packages. Fixes #5189, fixes #5179
[fix] Postgres Search case sensitive. Fixes #3529
[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.