fix various typos in documentation

Signed-off-by: Matthias Kestenholz <matthias@spinlock.ch>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/git-diff-tree.txt

@@ -92,7 +92,7 @@ separated with a single space are given.
 	Furthermore, it lists only files which were modified
 	from all parents.
 
--cc::
+--cc::
 	This flag changes the way a merge commit patch is displayed,
 	in a similar way to the '-c' option. It implies the '-c'
 	and '-p' options and further compresses the patch output

Documentation/git-update-index.txt

@@ -11,7 +11,7 @@ SYNOPSIS
 [verse]
 'git-update-index'
 	     [--add] [--remove | --force-remove] [--replace]
-	     [--refresh [-q] [--unmerged] [--ignore-missing]]
+	     [--refresh] [-q] [--unmerged] [--ignore-missing]
 	     [--cacheinfo <mode> <object> <file>]\*
 	     [--chmod=(+|-)x]
 	     [--assume-unchanged | --no-assume-unchanged]

revision.c

@@ -537,7 +537,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 				revs->max_count = atoi(arg + 12);
 				continue;
 			}
-			/* accept -<digit>, like traditilnal "head" */
+			/* accept -<digit>, like traditional "head" */
 			if ((*arg == '-') && isdigit(arg[1])) {
 				revs->max_count = atoi(arg + 1);
 				continue;