Update oik-i18n for PHP 7.0, 7.1 and 7.2

[bobbingwide]

oik-i18n, initially written in 2Q/3Q 2013, was built to extend WordPress's makepot solution to support the higher level API's used in the oik suite of plugins.

A number of things need to be done

1. It needs to be under version control
2. The code needs updating for PHP 7
3. It should attempt to take advantage of the solution delivered for plugins & themes on WordPress.org

This issue is for the first two items in the list.

• The files in the pomo directory should be updated to match the current version in WordPress.
• makeoik.php should be updated to reflect improvements in makepot.php

[bobbingwide]

I'm going to defer updating the code to match the current version in WordPress since there are some functional changes that I need to apply anyway.

1. Ignore the tests/ directory when building .pot files
2. Cater for nested rules during the transition from the custom rules set in makeoik to the standard rules set in makepot. We need to be able to support calls such as

BW_::p( __( "string" )); 
p( "string" );

Without a minor change to the code the invocation of __() in the first line of the example is not found.

[bobbingwide]

PHP is now at 7.2. Some parts of oik-i18n need changing to run correctly under PHP 7.2

Errors from oik-wp running l10n.php

[0] => 8192
[1] => Deprecated: Function create_function() is deprecated
[2] => C:\apache\htdocs\wordpress\wp-content\plugins\oik-i18n\makeoik.php
[3] => 242

[0] => 8192
[1] => Deprecated: Function create_function() is deprecated
[2] => C:\apache\htdocs\wordpress\wp-content\plugins\oik-i18n\pomo\po.php
[3] => 174

[bobbingwide]

Now that makeoik.php is run in a WordPress environment we should be able to use the files from wp-includes/Pomo rather than our local version. Also check how pot-ext-meta.php is supposed to be used; compare with oik-ext-meta.php

[bobbingwide]

I've been running the routines with PHP 7.4 for a while now. Next time it'll be compatibility with PHP 8.