Protocol spec: fix incompatibility with recent TeXLive.

Signed-off-by: Daira Hopwood <daira@jacaranda.org>

protocol/protocol.tex

@@ -5,7 +5,6 @@
 \usepackage{amsthm}
 \usepackage{bytefield}
 \usepackage{graphicx}
-\usepackage{newtxmath}
 \usepackage{mathtools}
 \usepackage{xspace}
 \usepackage{url}
@@ -31,7 +30,7 @@
 \usepackage{tocloft}
 \usepackage{pict2e}
 
-\usepackage[style=alphabetic,maxbibnames=99,dateabbrev=false,urldate=iso8601,
+\usepackage[style=alphabetic,maxbibnames=99,dateabbrev=false,urldate=edtf,seconds=true,
             backref=true,backrefstyle=none,backend=biber]{biblatex}
 \addbibresource{zcash.bib}
 
@@ -40,7 +39,6 @@
 \usepackage{quattrocento}
 \usepackage[bb=ams]{mathalfa}
 \usepackage[scr]{rsfso}
-%\usepackage{txfonts}
 
 % Quattrocento is beautiful but doesn't have an italic face. So we scale
 % New Century Schoolbook italic to fit in with slanted Quattrocento and
@@ -307,6 +305,34 @@
 \DeclareSymbolFont{matha}{OML}{txmi}{m}{it}
 \DeclareMathSymbol{\varv}{\mathord}{matha}{118}
 
+% newmathtx defines some nice characters, but has too many side effects
+% and is completely incompatible with lmodern. We pull these definitions out
+% of <newmathtx.sty>.
+
+% from <https://tex.stackexchange.com/q/452081/78411>
+\makeatletter
+\newif\iftx@libertine
+\newif\iftx@minion
+\newif\iftx@coch
+\makeatother
+
+\DeclareSymbolFont{lettersA}{U}{ntxmia}{m}{it}
+\SetSymbolFont{lettersA}{bold}{U}{ntxmia}{b}{it}
+\DeclareFontSubstitution{U}{ntxmia}{m}{it}
+
+\DeclareMathSymbol{\uprho}{\mathord}{lettersA}{26}
+\DeclareMathSymbol{\upvarphi}{\mathord}{lettersA}{39}
+
+\DeclareSymbolFont{AMSm}{U}{ntxsym}{m}{n}
+\SetSymbolFont{AMSm}{bold}{U}{ntxsym}{b}{n}
+\DeclareFontSubstitution{U}{ntxsym}{m}{n}
+
+\DeclareMathSymbol{\Game}{\mathord}{AMSm}{97}
+\DeclareMathSymbol{\ggg}{\mathrel}{AMSm}{239}
+\DeclareMathSymbol{\circledast}{\mathbin}{AMSm}{254}
+
+% end of characters from newmathtx
+
 \newcommand{\hairspace}{~\!}
 \newcommand{\oparen}{\big(}
 \newcommand{\hparen}{\phantom{\oparen}}
@@ -9942,6 +9968,15 @@ Peter Newell's illustration of the Jubjub bird, from \cite{Carroll1902}.
 \section{Change History}
 
 
+\subparagraph{2019.0.2}
+2019-06-18
+
+\begin{itemize}
+    \item Ensure that this document builds correctly and without missing
+          characters on recent versions of \TeX Live.
+\end{itemize}
+
+\introlist
 \subparagraph{2019.0.1}
 2019-05-20