use Parsica 0.8.1

Update to using Parsica 0.8.1, which presents an approx 2x speed-up for KDL parsing compared with the previous release! (standard benchmarking disclaimers apply, YMMV)

use new Parsica package name/ PHP namespace

The Parsica library in v0.7 has moved to its own org in Packagist, and its own vendor name in PHP. This new release switches to using that. There are no behavioural changes in this release.

use Kdl vendor namespace

Release breaks BC as the vendor namespace has changed from Shieldo to Kdl.
The parse operation also now clears internally memoised parser objects on completion.

parser memoisation

This release adds some memoisation of parser objects for individual parts of the KDL grammar once they are instantiated. A very modest speed increase is observed (3% or so, unscientifically) without obfuscating the code unduly.

0.1.0 - full implementation, but slow

This is the first release (pre-1.0) of this parser for the KDL document format.

It passes all tests for the JS and Rust implementations, give or take a quibble about the spec.

It's... slow! For now! The underlying library, Parsica, has yet to focus on speed, and there are likely some optimisations (memoisations and the like) that this library can perform on top of that. The aim is absolutely to increase parse speed significantly, although it will of course remain a PHP implementation and therefore will be less performant than a parser in e.g. Rust.

Please report any issues found!