agent: Move a typedef to common and provide parse_pinentry_mode.

* common/agent-opt.c: New.
* common/shareddefs.h: New.
* common/Makefile.am: Add new files.
* agent/agent.h: Include shareddefs.h.
(pinentry_mode_t): Factor out to shareddefs.h.
* agent/command.c (option_handler): Use parse_pinentry_mode.

common/shareddefs.h

@@ -0,0 +1,48 @@
+/* shareddefs.h - Constants and helpers useful for all modules
+ * Copyright (C) 2013 Free Software Foundation, Inc.
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of either
+ *
+ *   - the GNU Lesser General Public License as published by the Free
+ *     Software Foundation; either version 3 of the License, or (at
+ *     your option) any later version.
+ *
+ * or
+ *
+ *   - the GNU General Public License as published by the Free
+ *     Software Foundation; either version 2 of the License, or (at
+ *     your option) any later version.
+ *
+ * or both in parallel, as here.
+ *
+ * This file is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GNUPG_COMMON_SHAREDDEFS_H
+#define GNUPG_COMMON_SHAREDDEFS_H
+
+/* Values for the pinentry mode.  */
+typedef enum
+  {
+    PINENTRY_MODE_ASK = 0, /* Ask via pinentry (default).  */
+    PINENTRY_MODE_CANCEL,  /* Always return a cancel error.  */
+    PINENTRY_MODE_ERROR,   /* Return error code for no pinentry.  */
+    PINENTRY_MODE_LOOPBACK /* Use an inquiry to get the value.    */
+  }
+pinentry_mode_t;
+
+
+/*-- agent-opt.c --*/
+int parse_pinentry_mode (const char *value);
+const char *str_pinentry_mode (pinentry_mode_t mode);
+
+
+
+#endif /*GNUPG_COMMON_SHAREDDEFS_H*/