lib/base: introduce HEIM_BASE_USE_PATH_TOKENS

KRB5_USE_PATH_TOKENS cannot be used within lib/base as its value
is declared in lib/krb5/krb5.h.  Declare HEIM_BASE_USE_PATH_TOKENS
in lib/base/baselocl.h and test for it in
heim_config_parse_file_multi().

By conditionalizing heim_config_parse_file_multi() behavior on
KRB5_USE_PATH_TOKENS heim_expand_path_tokens() is not executed
and open() is called on a path without token substitution.  As a
result open() always fails with ENOENT.

Change-Id: I29dc018bc560519b76314232b2d51f53bde6313c

lib/base/log.c

@@ -35,6 +35,7 @@
 
 #include "baselocl.h"
 #include "heim_threads.h"
+#include "heimbase.h"
 #include "heimbase-svc.h"
 #include <assert.h>
 #include <stdarg.h>