Use c99 standard and DREENTRANT for thread save libc

configure.ac

@@ -57,6 +57,9 @@ AM_CFLAGS="${AM_CFLAGS} ${MEM_OPT_FLAGS}"
 AM_CFLAGS="${AM_CFLAGS} ${CFLAGS}"
 AC_SUBST(AM_CFLAGS)
 
+AM_LDFLAGS=""
+AC_SUBST(AM_LDFLAGS)
+
 AC_CONFIG_FILES([Makefile
 		 docs/Makefile
 		 tests/Makefile

src/Makefile.am

@@ -1,7 +1,8 @@
 ACLOCAL_AMFLAGS = -I m4
 AUTOMAKE_OPTIONS = subdir-objects
 
-AM_CFLAGS += -I../include/
+AM_CFLAGS += -I../include/ -std=c99 -DREENTRANT -lpthread
+AM_LDFLAGS += -lpthread
 
 TRIO = stream.c \
        read.c \
@@ -26,3 +27,4 @@ lib_LTLIBRARIES = libtrio.la
 libtrio_la_SOURCES = $(TRIO)
 libtrio_la_CFLAGS  = $(AM_CFLAGS)
 libtrio_la_LIBADD  =
+libtrio_la_LDFLAGS = -version-info 0:0:0 $(AM_LDFLAGS)