The Events Calendar - Community Events Tickets 4.9.5

* Feature - Add check and enforce PHP 5.6 as the minimum version [116283]
* Feature - Add system to check plugin versions to inform you to update and prevent site breaking errors [116841]
* Tweak - Update tooltip to clarify subscribers cannot manage attendees [103974]
* Tweak - Update plugin header [90398]
* Tweak - Added filters: `tribe_not_php_version_names`
* Deprecated - The constants `REQUIRED_TEC_VERSION` and `REQUIRED_ET_VERSION`, `autoloading()` and `register_active_plugin()` method has been deprecated in `Tribe__Events__Community__Tickets__Main` in favor of Plugin Dependency Checking system

* Fix - Fix the textdomain in a number of strings to ensure the translated version of them shows as expected

* Tweak - Remove references to purchase limit options [105775]
* Deprecated - `get_purchase_limit()` on `Tribe__Events__Community__Tickets__Main`
* Deprecated - `enforce_purchase_limit_on_add()` on `Tribe__Events__Community__Tickets__Main`
* Deprecated - `enforce_purchase_limit_on_update()` on `Tribe__Events__Community__Tickets__Main`
* Deprecated - `set_purchase_limit()` on `Tribe__Events__Community__Tickets__Main`
* Deprecated - `maybe_display_purchase_limit()` on `Tribe__Events__Community__Tickets__Main`