Initial release of newxml done!

[solidstate1991]

https://github.com/ZILtoid1991/newxml/releases/tag/v0.2.0

It's a heavily modified `std.experimental.xml` with the following 
changes:

* Many templating have been removed in favor of other forms of 
setting. This means the allocators have been axed in favor of 
using `new` and relying on D's automatic garbage collection.
* Has a proper DOMString implementation. This might make a few 
things a bit slower, but also simplified things.
* Has way more error handling than the original, and at parsing 
time (More will be added down the line).
* And of course, it's being actively developed.

DOM compatibility means that anyone who worked with any other DOM 
implementation (C++, Java, Python, JS, etc.) will be immediately 
familiar with it. For SAX, I went after my own head, and before 
1.0, I can still change it if I need based on user feedback. I 
might also port `legacy.d` for those who used to use the old 
`std.xml` implementation.