Make .o files in separate subdirectories for servald and library
Factor struct __sourceloc and __WHENCE__ from "log.h" into "whence.h"
Factor sid_t etc from "serval.h" into "serval_types.h"
Factor rhizome_bid_t etc from "rhizome.h" into "rhizome_types.h"
Do not include "serval.h" in library sources
Add log_stderr.c and logMessage.c for stand-alone executables
Configurable rules file path: mdp.filter_rules_path
Add filter rules parsing code, add filtering to outgoing as well as
incoming packets
New test script: tests/mdp with two test cases
Improve test defs: new execute_servald() function
Widen MDP port number format from 8 to ten chars to accommodate leading
"0x"
