avoid curly single quotes by using upquote package

The curly quotes cause syntax error (or lack of functionality)
when copy pasted from the PDF into terminal, such as the case of the find(1)
command.

Author: Vladimir Kotal

common.tex

@@ -63,6 +63,8 @@
 %\usepackage{pstricks} % does not work with colortbl
 %\usepackage{colortbl}
 
+\usepackage{upquote}
+
 %%% Macros %%%
 
 % colored frame around source code path to examples

threads.tex

@@ -1551,8 +1551,7 @@
 try running \texttt{apropos \_np}, or using brute-force (use the location
 of man pages on given system):
 \begin{verbatim}
-$ cd /usr/share/man
-$ find . -name '*_np\.*'
+$ find /usr/share/man/ -type f -name '*_np\.*'
 ./man3c/mq_reltimedreceive_np.3c
 ./man3c/mq_reltimedsend_np.3c
 ./man3c/posix_spawnattr_getsigignore_np.3c