Programmable debugger

[huanghantao]

In the next version of yasd, we will support init files. In the debugger initialization phase, this script will be executed. In this way, we have many benefits, the following is what I can think of:

1. We can provide some methods to configure yasd so that the configuration can be moved into the script. With the help of IDE's auto-completion, we can quickly configure the debugger, and we can easily comment the configuration items.
2. We can pass configurations like objects and arrays to yasd.
3. We can modify the behavior of yasd during runtime.
4. Just imagine, if you want to set breakpoints for all functions starting with test*, we can accomplish this function through a simple initialization file.
5. Analyze the running status of the program, for example, provide an api, when the function execution exceeds the specified time, it will call back a user-registered function：

namespace Yasd\Api
{
    /**
     * @param int $milliseconds
     * @param callable $func
     * @return void
     */
    function onGreaterThanMilliseconds(int $milliseconds, callable $func) { }
}

6. We can make the configuration plug-in.