stubdom: Add autoconf

Stub domains now use autoconf to build.
This configure script can enable or disable specific domains
and also specify custom download locations for stubdom library
packages. See ./configure --help for details.

C and Caml are disabled by default. vtpm-stubdom is conditional
on the presense of cmake.

Rename vtpmmgrdom to vtpmmgr-stubdom

Also update .*ignore

Signed-off-by: Matthew Fioravante <matthew.fioravante@jhuapl.edu>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>

m4/pthread.m4

@@ -0,0 +1,41 @@
+# We define, separately, PTHREAD_CFLAGS, _LDFLAGS and _LIBS
+# even though currently we don't set them very separately.
+# This means that the makefiles will not need to change in
+# the future if we make the test more sophisticated.
+
+AC_DEFUN([AX_PTHREAD_CV2VARS],[
+    PTHREAD_CFLAGS="$ax_cv_pthread_flags"
+    PTHREAD_LDFLAGS="$ax_cv_pthread_flags"
+    PTHREAD_LIBS=""
+])
+
+# We invoke AX_PTHREAD_VARS with the name of another macro
+# which is then expanded once for each variable.
+AC_DEFUN([AX_PTHREAD_VARS],[$1(CFLAGS) $1(LDFLAGS) $1(LIBS)])
+
+AC_DEFUN([AX_PTHREAD_VAR_APPLY],[
+    $1="$$1 $PTHREAD_$1"
+])
+AC_DEFUN([AX_PTHREAD_VAR_SUBST],[AC_SUBST(PTHREAD_$1)])
+
+AC_DEFUN([AX_CHECK_PTHREAD],[
+    AC_CACHE_CHECK([for pthread flag], [ax_cv_pthread_flags], [
+        ax_cv_pthread_flags=-pthread
+        AX_PTHREAD_CV2VARS
+        AX_PTHREAD_VARS([AX_SAVEVAR_SAVE])
+        AX_PTHREAD_VARS([AX_PTHREAD_VAR_APPLY])
+        AC_LINK_IFELSE([AC_LANG_SOURCE([
+#include <pthread.h>
+int main(void) {
+  pthread_atfork(0,0,0);
+  pthread_create(0,0,0,0);
+}
+])],[],[ax_cv_pthread_flags=failed])
+        AX_PTHREAD_VARS([AX_SAVEVAR_RESTORE])
+    ])
+    if test "x$ax_cv_pthread_flags" = xfailed; then
+        AC_MSG_ERROR([-pthread does not work])
+    fi
+    AX_PTHREAD_CV2VARS
+    AX_PTHREAD_VARS([AX_PTHREAD_VAR_SUBST])
+])