This creates a "document" class with only user-facing document state (no parser internals).
- document: user-facing document state
- document::iterator: iterator (equivalent of ParsedJsonIterator)
- document::parser: parser state plus a "docked" document we parse into (equivalent of ParsedJson)
Usage:
```c++
auto doc = simdjson::document::parse(buf, len); // less efficient but simplest
```
```c++
simdjson::document::parser parser; // reusable parser
parser.allocate_capacity(len);
simdjson::document* doc = parser.parse(buf, len); // pointer to doc inside parser
doc = parser.parse(buf2, len); // reuses all buffers and overwrites doc; more efficient
```
* Fix issue472: make JsonStream a template.
* Adding missing include.
* Tweaking headers and some minor formatting.
* Removing file from aggregation.
* Moving jsoncharutils
* Adding new header.
* Trying another header.
* Let us try to route around Visual Studio's nonesense.
* Fix for issue467
* Updating single-header
* Let us make it so that JsonStream is constructed from a padded_string which will avoid dangerous overruns.
* Fixing parse_stream
* Updating documentation.
John Keiser
Daniel Lemire
ioioioio