Commit Brian Olson's gzip stream implementations.
diff --git a/configure.ac b/configure.ac
index 6015281..2824960 100644
--- a/configure.ac
+++ b/configure.ac
@@ -15,6 +15,11 @@
 AC_CONFIG_MACRO_DIR([m4])
 AM_INIT_AUTOMAKE
 
+AC_ARG_WITH([zlib],
+  [AS_HELP_STRING([--with-zlib],
+    [include classes for streaming compressed data in and out @<:@default=check@:>@])],
+  [],[with_zlib=check])
+
 # Checks for programs.
 AC_PROG_CC
 AC_PROG_CXX
@@ -38,6 +43,16 @@
 AC_FUNC_STRTOD
 AC_CHECK_FUNCS([ftruncate memset mkdir strchr strerror strtol])
 
+HAVE_ZLIB=0
+AS_IF([test "$with_zlib" != no],
+  [AC_SEARCH_LIBS([zlibVersion], [z],
+    [AC_DEFINE([HAVE_ZLIB], [1], [Enable classes using zlib compression.])
+     HAVE_ZLIB=1],
+    [if test "$with_zlib" != check; then
+      AC_MSG_FAILURE([--with-zlib was given, but test for zlib failed])
+     fi])])
+AM_CONDITIONAL([HAVE_ZLIB], [test $HAVE_ZLIB = 1])
+
 ACX_PTHREAD
 AC_CXX_STL_HASH