Merge pull request #44 from hvr/pr/configure

Tweaks to configure.ac

configure.ac

@@ -3,13 +3,14 @@ AC_INIT([Haskell time package], [1.6], [ashley@semantic.org], [time])
 # Safety check: Ensure that we are in the correct source directory.
 AC_CONFIG_SRCDIR([lib/include/HsTime.h])
 
-AC_ARG_WITH([cc],
-            [C compiler],
-            [CC=$withval])
+# These are to silence warnings with older Cabal versions
 AC_ARG_WITH([gcc],[Gnu C compiler])
 AC_ARG_WITH([compiler],[Haskell compiler])
+
 AC_PROG_CC()
 
+AC_USE_SYSTEM_EXTENSIONS
+
 AC_CONFIG_HEADERS([lib/include/HsTimeConfig.h])
 
 AC_CHECK_HEADERS([time.h])