New command line options for configuration

Added new command line options to 'dnscache' server to specify
configuration(-c), log(-l) & pid(-p) files and also the server
port(-P) number.

These options would help if user wants to run multiple instances
of the server with different configurations, listening on different
ports, on the same host.
New command line options for axfrdns

Added new command line options to 'axfrdns' server to specify
configuration(-c), log(-l) & pid(-p) files.

These options would help if a user wants to run multiple instances
of the server with different configurations on the same host.
New command line options for tinydns

Added new command line options to 'tinydns' server to specify
configuration(-c), log(-l) & pid(-p) files and also the server
port(-P) number.

These options would help if user wants to run multiple instances
of the server with different configurations, listening on different
ports, on the same host.