Fixed captitalization in bitcoin-cli-res.rc
RPC cleanup: Improve HTTP server replies

1) support varying content types
2) support only sending the header
3) properly deliver error message as content, if HTTP error
4) move AcceptedConnection class to header, for wider use
RPC code movement: separate out JSON-RPC execution logic from HTTP server logic
Move AcceptedConnection class to rpcserver.h.

Also, add parens to HTTPReply() to assist readability.
Merge pull request #4424

c598f2a Fixed captitalization in bitcoin-cli-res.rc (Whit J)
Merge pull request #4288

ed5769f Move AcceptedConnection class to rpcserver.h. (Jeff Garzik)
854d013 RPC code movement: separate out JSON-RPC execution logic from HTTP server logic (Jeff Garzik)
c912e22 RPC cleanup: Improve HTTP server replies (Jeff Garzik)
rpc-tests: Fix rpcbind_test after 0193fb8

Port number for RPC is no longer static as multiple tests could be
running at once.