For non-Windows platforms, the default paths for awk, diff, gzip are
fixed at compile time since these are standard utilities for these
platforms. However, for Windows, we ship these utilities along with
Ostinato, so we need to set default path as the application directory
which is known only at run time. This is done as part of
Preferences::initDefaults() and therefore should be called before
setting OstProtoLib external program paths
Enable logs if '-d' command-line option is given.
Additional command-line options -
-v : print version
-h : print usage
Drone only:
-p <port-number> : use given port number for the RPC service
