Implement a parser for ircv3 and add unit tests to it.
This change got pretty big so I didn't implement unescapping tags yet. I did
however put the unit tests in for escaped tags, but they are currently #if 0'd
out.
The unit tests are based on the msg-split test cases from https://github.com/ircdocs/parser-tests/blob/master/tests/msg-split.yaml
Testing Done:
Ran the unit tests.
Bugs closed: PIDGIN-17585
Reviewed at https://reviews.imfreedom.org/r/1874/
# SOME DESCRIPTIVE TITLE.
# Copyright (C) YEAR THE PACKAGE'S COPYRIGHT HOLDER
# This file is distributed under the same license as the PACKAGE package.
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# Translators:
# Copyright (C) Artur Flinta <aflinta@at.kernel.pl>, 2004
# Copyright (C) Krzysztof Foltman <kfoltman@onet.pl>, 2003
# Copyright (C) Paweł Godlewski <pawel@endure.pl>, 2007
# Piotr Drąg <piotrdrag@gmail.com>, 2009
# Copyright (C) Piotr Makowski <pmakowski@aviary.pl>, 2008