Remove the configure check for Boost, since we do not use it anymore.

* README: Do not mention Boost.
* configure.ac: Do not check for Boost.
* m4/boost.m4: Delete.

README

@@ -33,8 +33,6 @@ later).  Especially, Python's headers files should be installed.  If
 you don't have Python installed, you should run configure with
 the --disable-python option (see below).
 
-The Boost libraries should also be installed.
-
 
 Third-party dependencies
 ------------------------

configure.ac

@@ -108,7 +108,6 @@ fi
 
 AX_CHECK_BUDDY
 AX_CHECK_GSPNLIB
-AX_CHECK_BOOST([1.34], [103400])
 
 AC_CHECK_HEADERS([sys/times.h])
 AC_CHECK_FUNCS([times srand48 drand48 kill alarm])

m4/boost.m4

-AC_DEFUN([AX_CHECK_BOOST],
-[
-AC_LANG_PUSH([C++])
-
-AC_CHECK_HEADER([boost/version.hpp],, [AC_MSG_ERROR([
-Cannot find Boost headers.  If they are installed on an unusuall path on
-your system, please run configure with the suitable CPPFLAGS and LDFLAGS
-options.  For instance if it is installed in /opt/boost/ please use:
-
-  ./configure CPPFLAGS="-I/opt/boost/include" LDFLAGS="-L/opt/boost/lib"
-])])
-
-AC_CACHE_CHECK([whether Boost version is >= $1], [ac_cv_boost_recent],
-[AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-@%:@include <boost/version.hpp>
-]], [[
-#if BOOST_VERSION >= $2
-// Everything is okay
-#else
-#  error Boost version is too old
-#endif
-]])],[
-ac_cv_boost_recent=yes
-],[
-ac_cv_boost_recent=no
-])])
-if test "x$ac_cvboost_recent" = xno; then
-  AC_MSG_ERROR([Boost appears to be too old.  We need version $1 or more recent.])
-fi
-
-AC_LANG_POP([C++])
-])