create common proc_tools

proc_put, proc_get and proc_get_hex are used in many files.
Avoid duplication by moving them to common/proc_tools.c.
Convert azbox's cVideo to use proc_tools.h

common/proc_tools.h

@@ -0,0 +1,20 @@
+/*
+ * helper functions to interact with files, usually in the proc filesystem
+ *
+ * (C) 2012 Stefan Seyfried <seife@tuxboxcvs.slipkontur.de>
+ *
+ * License: GPLv2 or later
+ *
+ */
+#ifndef __PROC_TOOLS_H__
+#define __PROC_TOOLS_H__
+#ifdef __cplusplus
+extern "C" {
+#endif
+int proc_put(const char *path, const char *value, const int len);
+int proc_get(const char *path, char *value, const int len);
+unsigned int proc_get_hex(const char *path);
+#ifdef __cplusplus
+}
+#endif
+#endif