[#1722] Make sure pcre is available

sflphone-common/configure.ac

@@ -214,6 +214,12 @@ AC_SUBST(libssl_LIBS)
 	AC_SUBST(ZRTPCPP_LIBS)
 AC_SUBST(ZRTPCPP_CFLAGS)
 
+	dnl Check for libpcre
+#	LIBPCRE_MIN_VERSION=0.0.0
+#	PKG_CHECK_MODULES(PCRE, libpcre >= ${LIBPCRE_MIN_VERSION})
+#	AC_SUBST(PCRE_LIBS)
+#AC_SUBST(PCRE_CFLAGS)
+
 
 dnl DBus-C++ detection (used to be in library own build system)
 	DBUS_REQUIRED_VERSION=0.60
@@ -295,6 +301,15 @@ AC_CHECK_LIB([pthread], pthread_create,
 AC_MSG_ERROR([You need the POSIX Thread library (pthreads)])	
 	fi
 
+AC_CHECK_LIB([pcre], pcre_free,
+		[AC_CHECK_HEADERS(pcre.h, have_pcre=true, have_pcre=false)],
+		have_pcre=false)
+
+	if test "$have_pcre" = "false"; then
+AC_MSG_ERROR([You need the Perl-Compatible Regular Expressions library (pcre)])	
+	fi
+
+
 # For the tools/, we need libdbus-c++ for the "build" architecture as well
 
 	AM_CONDITIONAL(CROSS_COMPILING, test "$cross_compiling" = "yes")