Refactored merge options into separate merge-options.txt.

Refactored fetch options into separate fetch-options.txt.
Made git-merge use merge-options.
Made git-fetch use fetch-options.
Made git-pull use merge-options and fetch-options.
Added --help option to git-pull and git-format-patch scripts.
Rewrote Documentation/Makefile to dynamically determine
include dependencies.

Signed-off-by: Jon Loeliger <jdl@freescale.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/fetch-options.txt

@@ -0,0 +1,14 @@
+-a, \--append::
+	Append ref names and object names of fetched refs to the
+	existing contents of `.git/FETCH_HEAD`.  Without this
+	option old data in `.git/FETCH_HEAD` will be overwritten.
+
+-f, \--force::
+
+-t, \--tags::
+
+-u, \--update-head-ok::
+	By default `git-fetch` refuses to update the head which
+	corresponds to the current branch.  This flag disables the
+	check.  Note that fetching into the current branch will not
+	update the index and working directory, so use it with care.