sysdb: Implemented input scanner and simple command handling.

sysdb: Implemented input scanner and simple command handling.

Reused the frontend parser lexer to identify single queries (terminated by
semicolon). No other parsing of the command is done by the client to make the
frontend the ultimate truth in regard to the parser (including simple stuff
like comments).

The query is then sent to the daemon and the reply will be printed to the
standard output channel.