completion: add diff --color-moved[-ws]

These options are available since git v2.15, but somehow
eluded from the completion script.

Note that while --color-moved-ws= accepts comma-separated
list of values, there is no (easy?) way to make it work
with completion (see e.g. [1]).

[1]: https://github.com/scop/bash-completion/issues/240

Acked-by: Matheus Tavares Bernardino <matheus.bernardino@usp.br>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/completion/git-completion.bash

@@ -1470,9 +1470,16 @@ __git_diff_algorithms="myers minimal patience histogram"
 
 __git_diff_submodule_formats="diff log short"
 
+__git_color_moved_opts="no default plain blocks zebra dimmed-zebra"
+
+__git_color_moved_ws_opts="no ignore-space-at-eol ignore-space-change
+			ignore-all-space allow-indentation-change"
+
 __git_diff_common_options="--stat --numstat --shortstat --summary
 			--patch-with-stat --name-only --name-status --color
 			--no-color --color-words --no-renames --check
+			--color-moved --color-moved= --no-color-moved
+			--color-moved-ws= --no-color-moved-ws
 			--full-index --binary --abbrev --diff-filter=
 			--find-copies-harder --ignore-cr-at-eol
 			--text --ignore-space-at-eol --ignore-space-change
@@ -1503,6 +1510,14 @@ _git_diff ()
 		__gitcomp "$__git_diff_submodule_formats" "" "${cur##--submodule=}"
 		return
 		;;
+	--color-moved=*)
+		__gitcomp "$__git_color_moved_opts" "" "${cur##--color-moved=}"
+		return
+		;;
+	--color-moved-ws=*)
+		__gitcomp "$__git_color_moved_ws_opts" "" "${cur##--color-moved-ws=}"
+		return
+		;;
 	--*)
 		__gitcomp "--cached --staged --pickaxe-all --pickaxe-regex
 			--base --ours --theirs --no-index