I now fully understand the MIDAS RPC code, had to add some debugging printfs, 
write some test code (odbedit test_rpc), catch and fix a few bugs.

Fixes for the bugs are now committed.

Small refactor of rpc_execute() should be committed soon, this removes the 
"goto" in the memory allocation of output buffer. Stefan's original code used a 
fixed size buffer, I later added allocation "as-neeed" but did not fully 
understand everything and implemented it as "if buffer too small, make it 
bigger, goto start over again".

After that, I can implement support for std::string and std::vector<char>.

The way it looks right now, the on-the-wire data format is flexible enough to 
make this change backward-compatible and allow MIDAS programs built with old 
MIDAS to continue connecting to the new MIDAS and vice-versa.

MIDAS RPC support for std::string should let us improve security by removing 
even more uses of fixed-size string buffers.

Support for std::vector<char> will allow removal of last places where 
MAX_EVENT_SIZE is used and simplify memory allocation in other "give me data" 
RPC calls, like RPC_JRPC and RPC_BRPC.

K.O.