Initial support for inline doctype and entities

[thekid]

Example

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE binford [
  <!ENTITY euro "&#8364;">
  <!ENTITY name "Binford &more;">
  <!ENTITY more "6100">
  <!ENTITY copy "Copyright">
]>
<binford power="&more;" price=".99 &euro;">&name; - &copy; 2021</binford>

Iteration yields the following:

['/' => 'Binford 6100 - Copyright 2021']
['//@power' => '6100']
['//@price' => '.99 €']

Notes

• Doesn't support external DTDs and raises exceptions if it encounters these
• Doesn't support external entities in inline DTDs such as <!ENTITY SYSTEM "http://www.xmlwriter.net/copyright.xml"> for security reasons and ignores these

See #12

[thekid]

Released in https://github.com/xp-forge/address/releases/tag/v5.1.0