add a library of timeval manipulation functions, and change a large number of usses to use the new functions (bug #4504)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@6146 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/app_dumpchan.c

@@ -51,7 +51,7 @@ static int ast_serialize_showchan(struct ast_channel *c, char *buf, size_t size)
 	char cgrp[256];
 	char pgrp[256];
 	
-	gettimeofday(&now, NULL);
+	now = ast_tvnow();
 	memset(buf,0,size);
 	if (!c)
 		return 0;