REORG: tcp: move TCP bind/server keywords from proto_tcp.c to cfgparse-tcp.c

Let's continue the cleanup and get rid of all bind and server keywords
parsers from proto_tcp.c. They're now moved to cfgparse-tcp.c, just as
was done for ssl before 2.2 release. Nothing has changed beyond this.
Now proto_tcp.c is clean and only contains code related to binding and
connecting.
diff --git a/Makefile b/Makefile
index 42b3742..854194e 100644
--- a/Makefile
+++ b/Makefile
@@ -819,7 +819,7 @@
        src/ebsttree.o src/pipe.o src/hpack-enc.o src/fcgi.o                   \
        src/eb64tree.o src/dict.o src/shctx.o src/ebimtree.o                   \
        src/eb32tree.o src/ebtree.o src/dgram.o src/proto_udp.o                \
-       src/hpack-huff.o src/base64.o src/version.o
+       src/hpack-huff.o src/cfgparse-tcp.o src/base64.o src/version.o
 
 ifneq ($(TRACE),)
 OBJS += src/calltrace.o