4.0.0

• the library doesn't set session.cookie_lifetime to 0 anymore but to the number of seconds specified in the constructor; with this, finally, sessions can be kept alive even if the browser is closed - this fixes #40 and #5
• the library is not setting gc_probability and gc_divisor properties anymore - this can potentially break your code when updating, as there are now less arguments in the constructor method!
• the library does not set session.use_strict_mode anymore - see #37
• updated documentation regarding what configuration options are set automatically
• lots of minor bug fixes and source code formatting because we are now using PHPStan for static code analysis and PHP CodeSniffer for detecting coding standards violations, which are now PSR12-ish with a few of the rules excluded