Handle the \c escape character in Tex detection (badly).

Its absolutely a hack, but that's what I have the energy for right
now.

Closes #108, #106

lib/mimemagic/tables.rb

@@ -26,7 +26,16 @@ class MimeMagic
         offset = offset.size == 2 ? offset[0]..offset[1] : offset[0]
         case type
         when 'string'
-          value.gsub!(/\\(x[\dA-Fa-f]{1,2}|0\d{1,3}|\d{1,3}|.)/) { eval("\"\\#{$1}\"") }
+          # This *one* pattern match, in the entirety of fd.o's mime types blows up the parser
+          # because of the escape character \c, so right here we have a hideous hack to
+          # accommodate that.
+          if value == '\chapter'
+            '\chapter'
+          else
+            value.gsub!(/\\(x[\dA-Fa-f]{1,2}|0\d{1,3}|\d{1,3}|.)/) {
+              eval("\"\\#{$1}\"")
+            }
+          end
         when 'big16'
           value = str2int(value)
           value = ((value >> 8).chr + (value & 0xFF).chr)

test/files/text.x-tex

+\documentclass[12pt]{article}
+\usepackage{lingmacros}
+\usepackage{tree-dvips}
+\begin{document}
+
+\section*{Notes for My Paper}
+
+Don't forget to include examples of topicalization.
+They look like this:
+
+{\small
+\enumsentence{Topicalization from sentential subject:\\ 
+\shortex{7}{a John$_i$ [a & kltukl & [el & 
+  {\bf l-}oltoir & er & ngii$_i$ & a Mary]]}
+{ & {\bf R-}clear & {\sc comp} & 
+  {\bf IR}.{\sc 3s}-love   & P & him & }
+{John, (it's) clear that Mary loves (him).}}
+}
+
+\subsection*{How to handle topicalization}
+
+I'll just assume a tree structure like (\ex{1}).
+
+{\small
+\enumsentence{Structure of A$'$ Projections:\\ [2ex]
+\begin{tabular}[t]{cccc}
+    & \node{i}{CP}\\ [2ex]
+    \node{ii}{Spec} &   &\node{iii}{C$'$}\\ [2ex]
+        &\node{iv}{C} & & \node{v}{SAgrP}
+\end{tabular}
+\nodeconnect{i}{ii}
+\nodeconnect{i}{iii}
+\nodeconnect{iii}{iv}
+\nodeconnect{iii}{v}
+}
+}
+
+\subsection*{Mood}
+
+Mood changes when there is a topic, as well as when
+there is WH-movement.  \emph{Irrealis} is the mood when
+there is a non-subject topic or WH-phrase in Comp.
+\emph{Realis} is the mood when there is a subject topic
+or WH-phrase.
+
+\end{document}
\ No newline at end of file