clipboard: avoid clipboard during :global. #2809

This is equivalent to patches 7.4.396, 7.4.445 and 7.4.598.

vim-patch:7.4.396

Problem:    When 'clipboard' is "unnamed", :g/pat/d is very slow.
(Praful)
Solution:   Only set the clipboard after the last delete. (Christian
Brabandt)

1f285eb49a

vim-patch:7.4.445

Problem:    Clipboard may be cleared on startup.
Solution:   Set clip_did_set_selection to -1 during startup. (Christian
	    Brabandt)

1a19d37d90

vim-patch:7.4.598

Problem:    ":tabdo windo echo 'hi'" causes "* register not to be
changed.
	    (Salman Halim)
Solution:   Change how clip_did_set_selection is used and add
	    clipboard_needs_update and global_change_count.  (Christian
	    Brabandt)

af6a579263

Co-Author: @bfredl

src/nvim/version.c

@@ -323,7 +323,7 @@ static int included_patches[] = {
   601,
   600,
   599,
-  // 598,
+  598,
   597,
   // 596 NA
   595,
@@ -476,7 +476,7 @@ static int included_patches[] = {
   // 448 NA
   447,
   446,
-  // 445,
+  445,
   444,
   // 443 NA
   442,
@@ -525,7 +525,7 @@ static int included_patches[] = {
   // 399 NA
   // 398 NA
   397,
-  // 396,
+  396,
   395,
   // 394 NA
   // 393 NA