patch 8.2.0516: client-server code is spread out

Problem:    Client-server code is spread out.
Solution:   Move client-server code to a new file. (Yegappan Lakshmanan,
            closes #5885)
diff --git a/src/Makefile b/src/Makefile
index 221b4f0..704721b 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -1602,6 +1602,7 @@
 	change.c \
 	charset.c \
 	cindent.c \
+	clientserver.c \
 	clipboard.c \
 	cmdexpand.c \
 	cmdhist.c \
@@ -1747,6 +1748,7 @@
 	objects/blob.o \
 	objects/blowfish.o \
 	objects/cindent.o \
+	objects/clientserver.o \
 	objects/clipboard.o \
 	objects/cmdexpand.o \
 	objects/cmdhist.o \
@@ -1908,6 +1910,7 @@
 	channel.pro \
 	charset.pro \
 	cindent.pro \
+	clientserver.pro \
 	clipboard.pro \
 	cmdexpand.pro \
 	cmdhist.pro \
@@ -3123,6 +3126,9 @@
 objects/cindent.o: cindent.c
 	$(CCC) -o $@ cindent.c
 
+objects/clientserver.o: clientserver.c
+	$(CCC) -o $@ clientserver.c
+
 objects/clipboard.o: clipboard.c
 	$(CCC) -o $@ clipboard.c
 
@@ -3743,6 +3749,10 @@
  auto/osdef.h ascii.h keymap.h term.h macros.h option.h beval.h \
  proto/gui_beval.pro structs.h regexp.h gui.h alloc.h ex_cmds.h spell.h \
  proto.h globals.h
+objects/clientserver.o: clientserver.c vim.h protodef.h auto/config.h feature.h os_unix.h \
+ auto/osdef.h ascii.h keymap.h term.h macros.h option.h beval.h \
+ proto/gui_beval.pro structs.h regexp.h gui.h alloc.h ex_cmds.h spell.h \
+ proto.h globals.h
 objects/clipboard.o: clipboard.c vim.h protodef.h auto/config.h feature.h os_unix.h \
  auto/osdef.h ascii.h keymap.h term.h macros.h option.h beval.h \
  proto/gui_beval.pro structs.h regexp.h gui.h alloc.h ex_cmds.h spell.h \