Add openfst to external, as used by GoogleTTS

Moved from GoogleTTS

Change-Id: I6bc6bdadaa53bd0f810b88443339f6d899502cc8
diff --git a/configure.ac b/configure.ac
new file mode 100644
index 0000000..211dcd7
--- /dev/null
+++ b/configure.ac
@@ -0,0 +1,94 @@
+AC_INIT([OpenFst], [1.2.10], [help@www.openfst.org])
+AM_INIT_AUTOMAKE([foreign nostdinc -Wall -Werror])
+
+AC_PROG_CXX
+AC_DISABLE_STATIC
+AC_PROG_LIBTOOL
+
+AC_CONFIG_HEADERS([config.h src/include/fst/config.h])
+AC_CONFIG_SRCDIR([src/lib/fst.cc])
+AC_CONFIG_FILES([
+  Makefile
+  src/Makefile
+  src/include/Makefile
+  src/lib/Makefile
+  src/bin/Makefile
+  src/test/Makefile
+  src/extensions/Makefile
+  src/extensions/compact/Makefile
+  src/extensions/const/Makefile
+  src/extensions/far/Makefile
+  src/extensions/lookahead/Makefile
+  src/extensions/pdt/Makefile
+  src/script/Makefile
+])
+AC_CONFIG_MACRO_DIR([m4])
+AC_LANG([C++])
+
+AC_CHECK_TYPES([std::tr1::hash<long long unsigned>], [], [],
+               [[#include <tr1/unordered_map>]])
+AC_CHECK_TYPES([__gnu_cxx::slist<int>], [], [],
+               [[#include <ext/slist>]])
+
+AC_ARG_ENABLE(
+	[bin],
+	[AS_HELP_STRING(
+		[--enable-bin],
+		[enable fst::script and command-line binaries])],
+	[],
+	[enable_bin=yes])
+AM_CONDITIONAL([HAVE_BIN], [test "x$enable_bin" != xno])
+AM_CONDITIONAL([HAVE_SCRIPT], [test "x$enable_bin" != xno])
+
+AC_ARG_ENABLE(
+	[compact-fsts],
+	[AS_HELP_STRING(
+		[--enable-compact-fsts],
+		[enable all CompactFst extensions])],
+	[],
+	[enable_compact_fsts=no])
+AM_CONDITIONAL([HAVE_COMPACT], [test "x$enable_compact_fsts" != xno])
+				
+AC_ARG_ENABLE(
+	[const-fsts],
+	[AS_HELP_STRING(
+		[--enable-const-fsts],
+		[enable all ConstFst extensions])],
+	[],
+	[enable_const_fsts=no])
+AM_CONDITIONAL([HAVE_CONST], [test "x$enable_const_fsts" != xno])
+				
+AC_ARG_ENABLE([far], [AS_HELP_STRING([--enable-far], [enable FAR extensions])],
+              [], [enable_far=no])
+AM_CONDITIONAL([HAVE_FAR], [test "x$enable_far" != xno])
+
+AC_ARG_ENABLE(
+	[lookahead-fsts],
+	[AS_HELP_STRING(
+		[--enable-lookahead-fsts],
+		[enable LookAheadFst extensions])],
+	[],
+	[enable_lookahead_fsts=no])
+AM_CONDITIONAL([HAVE_LOOKAHEAD], [test "x$enable_lookahead_fsts" != xno])
+				
+AC_ARG_ENABLE([pdt], [AS_HELP_STRING([--enable-pdt], [enable PDT extensions])],
+              [], [enable_pdt=no])
+AM_CONDITIONAL([HAVE_PDT], [test "x$enable_pdt" != xno])
+
+AC_ARG_WITH([icu],
+  [AS_HELP_STRING([--with-icu],
+    [enable UTF8 support using the ICU Library])],
+  [],
+  [with_icu=no])
+AS_IF([test "x$with_icu" != xno],
+  [AC_CHECK_ICU(
+    [4.2],
+    [AC_DEFINE([HAVE_ICU],
+      [1],
+      [Define to 1 if you have the ICU library.])],
+    [AC_MSG_FAILURE(
+      [--with-icu was given, but ICU Library v. 4.2 or newer not found])])])
+
+AC_SUBST([libfstdir], [${libdir}/fst])
+
+AC_OUTPUT