Update Dockerfile for ttfautohint, update metrics

Summary:
Update the MathJaxFonts `Dockerfile` to enable the use of
`ttfautohint` which hints our fonts better. Also, fix the location that
batik is downloaded from, update some formatting in the `Dockerfile`,
and update the fonts and metrics.

Test Plan:
 - Compare a rendered `= - A z 4 \Longrightarrow \Sigma \Biggl(` in
   Chrome on Windows at font sizes 10px to 20px before and after this
   change.
 - See that characters look about the same, or better.
 - See that the screenshot tests didn't change in firefox (maybe firefox
   runs the same autohinting algorithm that we do?), and don't visually
   change in chrome

Reviewers: kevinb, alpert

Reviewed By: kevinb, alpert

Differential Revision: https://phabricator.khanacademy.org/D18977

dockers/MathJaxFonts/Dockerfile

@@ -2,8 +2,28 @@ FROM ubuntu:14.04
 MAINTAINER xymostech <xymostech@gmail.com>
 
 # Install things
-RUN apt-get -qq update
-RUN apt-get -qqy install git dvipng default-jre default-jdk texlive wget fontforge mftrace fonttools optipng advancecomp man-db build-essential unzip zlib1g-dev python-fontforge ruby woff-tools || true
+RUN apt-get -qq update && apt-get -qqy install \
+    git \
+    dvipng \
+    default-jre \
+    default-jdk \
+    texlive \
+    wget \
+    fontforge \
+    mftrace \
+    fonttools \
+    optipng \
+    advancecomp \
+    man-db \
+    build-essential \
+    unzip \
+    zlib1g-dev \
+    python-fontforge \
+    ruby \
+    woff-tools \
+    pkg-config \
+    libharfbuzz-dev \
+    libfreetype6-dev || true
 RUN gem install ttfunk --version 1.1.1
 
 # Download yuicompressor
@@ -11,7 +31,7 @@ RUN mkdir /usr/share/yui-compressor/
 RUN wget "https://github.com/yui/yuicompressor/releases/download/v2.4.8/yuicompressor-2.4.8.jar" -O /usr/share/yui-compressor/yui-compressor.jar
 
 # Download batik-ttf2svg.jar
-RUN wget "http://supergsego.com/apache/xmlgraphics/batik/batik-1.7.zip"
+RUN wget "https://archive.apache.org/dist/xmlgraphics/batik/batik-1.7.zip"
 RUN unzip -qq batik-1.7.zip
 RUN mv batik-1.7/batik-ttf2svg.jar /usr/share/java/
 
@@ -22,6 +42,13 @@ RUN sed -i "1s/^/#include <cstddef>/" ttf2eot-0.0.2-2/OpenTypeUtilities.h
 RUN make -C ttf2eot-0.0.2-2/
 RUN mv ttf2eot-0.0.2-2/ttf2eot /usr/bin/
 
+# Download and compile ttfautohint
+RUN wget "http://download.savannah.gnu.org/releases/freetype/ttfautohint-1.3.tar.gz"
+RUN tar -xzf ttfautohint-1.3.tar.gz
+RUN cd ttfautohint-1.3/ && ./configure --without-qt
+RUN make -C ttfautohint-1.3/
+RUN mv ttfautohint-1.3/frontend/ttfautohint /usr/bin
+
 # Download and compile woff2_compress
 RUN git clone "https://code.google.com/p/font-compression-reference/" woff2_compress
 RUN make -C woff2_compress/woff2/