Moved credential-related code to nxt_credential.c.

This is required to avoid include cycles, as some nxt_clone_* functions
depend on the credential structures, but nxt_process depends on clone
structures.

src/nxt_credential.h

@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) Igor Sysoev
+ * Copyright (C) NGINX, Inc.
+ */
+
+#ifndef _NXT_CREDENTIAL_H_INCLUDED_
+#define _NXT_CREDENTIAL_H_INCLUDED_
+
+
+typedef uid_t   nxt_uid_t;
+typedef gid_t   nxt_gid_t;
+
+typedef struct {
+    const char  *user;
+    nxt_uid_t   uid;
+    nxt_gid_t   base_gid;
+    nxt_uint_t  ngroups;
+    nxt_gid_t   *gids;
+} nxt_credential_t;
+
+
+NXT_EXPORT nxt_int_t nxt_credential_get(nxt_task_t *task, nxt_mp_t *mp,
+    nxt_credential_t *uc, const char *group);
+NXT_EXPORT nxt_int_t nxt_credential_set(nxt_task_t *task,
+    nxt_credential_t *uc);
+
+
+#endif /* _NXT_CREDENTIAL_H_INCLUDED_ */