Refactor code & implement autoloader

[stickz]

This pull request refactors the ruTorrent utility code to reduce script execution times and improve overall code readability. It moves all of the functions in php/util.php out of the global context and into classes. When the utility file is included, only the required functionality is added is each time. This prevents loading of unnecessary functionality for PHP scripts.

It implements a very basic auto loader function to simplify the including process of utility classes. The only file which needs to be included is php/util.php. When a utility class is used, PHP will automatically go to the /php/utility folder to include the file.

spl_autoload_register(function ($class) {
    require_once 'utility/'. strtolower($class). '.php';
});

Utility class names can have any mixture of lower or upper case letters. However, the files in the utility folder:

1. Must contain only 1 class per file.
2. Must end with the file extension .php.
3. Must have the same file name as the class inside of it.
4. Must have a file name in lower case letters only.

Other Notes:

1. The default value of profilePath variable had to be changed from ../share to ../../share. The reason is because it accessed from fileutil.php in /php/utility now instead of util.php in /php. The folder context is different to reach the root folder.

2. In the sqlite_exists() function in /plugins/geoip/sqlite.php the second argument class_exists had to be changed from true to false. It may be required to update the spl_autoload_register() function, if SQLite3 does not automatically load.

[stickz]

I added some instance caching of results for a few static methods as well. I found out preg_replace was being called on $_SERVER['REMOTE_USER'] about a hundred times during the plugin initialization phase.

[Novik]

Thanks, very massive pull request, I will check it later.

spl_autoload_register(function ($class) {
    require_once 'utility/'. strtolower($class). '.php';
});

1. I can see 'spl_autoload_register' in the list of changes. Maybe you forget to include some files?
2. This will not correctly work in such form. We need absolute path here, i.e. require_once __DIR__ . ...
3. Maybe, you will think about usage of composer instead?

[stickz]

spl_autoload_register is there. It's buried behind 760 lines of removed code in util.php. Everything worked when I tested this.

[Novik]

In the current implementation we may have several user's profiles for the single ruTorrent instllation.
And every user may have his own config.php file with a his own preferences (include profile path, proxy settings and so on).
How this feature will work after your changes?
Will class constants and variables be overridden correctly?

And even if yes, then now we have strange situation, when configuration partially inside global variables and partially in the class declarations. This is not good thing IMHO.
In the ideal situation we should to have only one global variable with something like this - https://github.com/hassankhan/config

[stickz]

There is a problem with user specific config.php files. I will fix this issue in a couple of days with anther commit.

[stickz]

I reverted the ruTorrentConfig class. A configuration loader can be added in anther pull request. This is beyond the intended scope of this pull request. The purpose here is to remove functions in php/util.php from the global scope.